ggs& 
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AN   INTRODUCTION   TO 
PSYCHOLOGY 


BY 
JAMES  ROWLAND  ANGELL 

Head  of  the  Department  of  Psychology  in  the  University 
of  Chicago 


NEW  YORK 

HENRY   HOLT  AND  COMPANY 
1920 


COPYRIGHT,  1918, 

BY 

HENRY  HOLT  AND  COMPANY 


TMI    QUINN    «    (ODIN    CO.     PHIBi 


LIST 

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I  a*NT*  u 

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£-2*  PREFACE 

SHORTLY  after  the  appearance  of  my  Psychology  in 
1904 x  I  began  to  receive  requests  from  teachers  to  pre- 
pare a  briefer  volume  on  the  same  general  lines.  This  I 
finally  agreed  to  do,  but  fulfilment  has  lagged  so  far  be- 
hind promise,  that  despite  the  continued  popularity  of 
the  older  work,  it  seems  no  longer  appropriate  to  attempt 
a  mere  digest  of  it.  The  present  book  accordingly  rep- 
resents an  entirely  fresh  survey  of  the  field,  and  attempts 
to  set  forth  simply  and  concisely  the  more  important  prin- 
ciples of  general  psychology.  Some  comment  upon  the 
relation  of  the  two  books  to  one  another  may  be  of  interest. 
The  prompt  welcome  accorded  the  earlier  work  was 
presumably  due  to  the  novelty  of  certain  of  its  features, 
which  have  since  been  adopted  in  greater  or  less  degree  by 
other  authors.  It  emphasized  for  the  first  time,  so  far  as 
I  am  aware,  the  distinction  between  structural  and  func- 
tional methods  in  psychology.  It  adopted  and  consistently 
utilized  an  essentially  biological  point  of  view  in  its  in- 
terpretation of  mental  life,  this  position  being  reflected  in 

^  part  in  the  arrangement  of  the  topics  to  exhibit  the  pro- 

?  gressive  stages_qf  adjustment.    It  presented,  provisionally 

to  be  sure,  a  definite  and  teachable  system,  which  gave 

. :   students  who  mastered  it  a  sense  of  control  over  the  ma- 

"-'  terial,  enabled  them  to  observe  and  think  psychologically 

for  themselves  and — not  least  important — afforded  them  a 

CN,  terminology  and  a  point  of  view  which  rendered  the  litera- 

1  Fourth  edition,  1908. 

iii 


iv  PREFACE 

ture  of  the  subject  easily  accessible.  Such  changes  as 
appear  in  the  present  text  simply  reflect  alterations  of 
emphasis  and  points  of  view  which  the  development  of  the 
science  has  rendered  necessary. 

The  structure-function  distinction  still  seems  to  me 
significant.  But  it  is  no  longer  a  matter  of  acute  con- 
troversy and  so  requires  a  less  militant  treatment.  Polemic 
is  now  centered  about  the  '  behavioristic '  movement, 
which,  with  its  gospel  of  objective  methods  and  its  crusade 
against  introspection,  presents  an  interesting  blend  of  solid 
contribution  and  adolescent  exaggeration.  Whatever  seems 
to  me  to  be  sound  in  its  position,  I  have  adopted.  It  lends 
itself  readily  to  incorporation  into  the  biological  concep- 
tion of  mental  activity,  which  I  have  retained  and  ener- 
getically pressed. 

The  organizing  character  of  every  level  of  our  psycho- 
motor  activities  is  more  explicitly  brought  out  than  in  the 
older  book,  with  advantage,  I  trust,  to  the  depth  and  vivid 
ness  of  impression  left  on  the  reader's  mind  regarding 
the  real  nature  of  our  adjustments  to  environment. 

I  have  come  in  recent  years  to  assign  more  importance 
than  I  formerly  did  to  the  function  of  subconscious  proc- 
esses in  our  behavior.  I  do  not  for  a  moment  accept  the 
A  prurient  implications  of  much  of  the  Freudian  doctrine, 
nor  have  I  been  greatly  influenced  by  any  of  its  conten- 
tions; but  on  other  grounds  I  have  come  to  the  belief 
that  there  is  a  large  element  of  intrinsically  intelligent 
control  in  many  neural  processes  which  escape  our  direct 
conscious  observation.  This  I  hold  to  be  as  true  of  re- 
flective thought  as  of  the  more  overt  control  of  our  muscles. 
The  text  will  be  found  to  reflect  something  of  this  con- 
viction. 


PREFACE  v 

My  views  on  the  function  of  imagery  have  been  a  good 
deal  misunderstood.  This  is  hardly  the  place  in  which 
to  confront  my  critics,  but  I  trust  that  the  present  text 
may  be  found  less  open  to  misapprehension.  With  the 
recently  developed  doctrine  of  'imageless  thought'  I  am 
warmly  sympathetic  so  far  as  it  has  served  to  direct  atten- 
tion to  the  meaning  aspect  of  our  mental  operations,  in 
distinction  from  their  mere  sensuous  texture.  Much  of 
its  pretense  to  novelty  I  think  is  based  on  the  miscon- 
struction of  earlier  doctrine.  Its  postulate  of  the  existence 
of  states  of  consciousness  wholly  devoid  of  sensorial  or 
imaginal  factors  I  regard  as  altogether  unsubstantiated. 

After  extended  conferences  with  teachers  I  have  decided 
to  omit  any  practical  exercises.  In  the  first  place  I  find 
that  many  instructors  prefer  to  prepare  their  own;  and 
in  the  second  place  there  are  now  a  number  of  admirable 
manuals  written  to  supply  this  precise  need.  I  consider 
such  exercises  an  essentially  indispensable  part  of  a  well- 
rounded  introductory  course,  but  they  need  not  be  made 
dependent  on  the  teachings  of  any  particular  text. 

For  the  use  of  a  number  of  illustrations  acknowledgments 
are  due  to  the  following  authors  and  publishers:  D.  Apple- 
ton  &  Co.,  publishers  of  Barker's  "The  Nervous  System"; 
Ginn  &  Co.,  publishers  of  "The  Elements  of  Physiology" 
by  T.  Hough  and  W.  T.  Sedgwick ;  John  Murray,  publisher 
of  "The  Physiology  of  the  Sense  Organs"  by  McKendrick 
and  Snodgrass;  G.  P.  Putnam's  Sons,  publishers  of  Loeb's 
"Physiology  of  the  Brain";  W.  B.  Saunders  &  Co.,  pub- 
lishers of  Howell's  "Text-Book  of  Physiology";  and  Wal- 
ter Scott,  Ltd.,  publishers  of  Donaldson's  "Growth  of  the 
Brain." 


vi  PREFACE 

I  am  under  many  obligations  to  my  former  students 
and  to  my  colleagues  at  the  University  of  Chicago  for 
suggestions  and  criticism.  My  wife  has  aided  me  greatly 
in  the  preparation  of  my  manuscript. 

J.  R.  A. 

CHICAGO, 

May  1,  1918. 

PREFACE  TO  SECOND  EDITION 

The  present  edition  contains  only  minor  alterations 
designed  to  add  useful  material  at  a  few  points  in  the  text, 
or  to  avoid  certain  infelicities  of  expression  to  which  atten- 
tion has  been  called. 

J.  R.  A. 

April  1,  1919. 


CONTENTS 

CHAPTER  FAGK 

I    PROBLEMS  AND  METHODS  OF  PSYCHOLOGY      .  1 

II    INHERITED  AND  ACQUIRED  BEHAVIOR       .       .  10 

III  THE  NERVOUS  SYSTEM 18 

IV  CONSCIOUSNESS  AND  HABIT  FORMATION  .       .  49 
V    ATTENTION 58 

VI    SENSATION 76 

VII    SENSE  PERCEPTION 114 

VIII    MEMORY 137 

IX    IMAGINATION .  152 

X    REASONING 170 

XI    FEELING 189 

XII    EMOTION 204 

XIII  INSTINCT 215 

XIV  ELEMENTS  OF  VOLUNTARY  ACTION  .        .       .  226 
XV    WILL,  INSTINCT,  AND  CHARACTER     .       .       .  237 

XVI    SLEEP,    DREAMS,    HYPNOSIS,    AND    MULTIPLE 

PERSONALITY     .       .       .       ...       .  249 

XVII    THE  SELF 263 

BIBLIOGRAPHY 273 

INDEX 279 


AN   INTRODUCTION  TO   PSYCHOLOGY 

CHAPTER  I 
PROBLEMS  AND  METHODS  OF  PSYCHOLOGY 

The  Subject  Matter  of  Psychology. — Old  and  well 
established  sciences  generally  feel  it  unnecessary  to  define 
themselves  for  the  benefit  of  the  beginner.  Young  sciences, 
on  the  other  hand,  commonly  seek  to  make  clear  the  field 
which  they  propose  to  occupy.  To  the  beginner,  any 
definition  of  a  science  must  be  somewhat  vague  and  formal, 
because  he  cannot  intelligently  interpret  its  real  meaning 
in  advance  of  a  knowledge  of  the  facts  with  which  the 
science  deals.  We  shall  therefore  make  no  serious  effort 
at  this  point  to  construct  a  precise  definition  of  psychology, 
which  is  the  youngest  of  the  biological  sciences.  It  is, 
however,  possible  to  give  rough  indications  of  a  helpful 
kind  regarding  the  general  character  of  the  problems  to 
be  confronted. 

The  older  definitions  of  psychology  spoke  of  it  as  'the 
science  of  the  soul,'  and  this  designation  was  long  em- 
ployed and  only  abandoned  at  last  because  of  the  many 
confusing  implications  of  the  word  soul.  Then  followed 
a  period  when  psychology  was  described  as  'the  science  of 
mind.'  In  its  turn  the  word  mind  in  this  definition  was 
abandoned  in  favor  of  the  term  'consciousness.'  In  each 
case  a  more  general  and  less  compromising  term  was  sub- 
stituted for  one  about  which  there  had  gathered  a  group 

1 


2      AN  INTRODUCTION  TO  PSYCHOLOGY 

of  irrelevant  or  misleading  associations.  Consciousness 
itself  has  now  fallen  victim  to  the  same  movement,  and  in 
its  place  we  are  urged  to  use  such  terms  as  'behavior,' 
'conduct,'  or  'intelligence.' 

At  this  juncture  it  is  far  less  important  to  secure  a 
verbally  precise  and  accurate  definition  than  it  is  to  gain 
a  fruitful  working  idea  of  the  general  range  of  facts  with 
which  psychology  deals,  and  the  technique  by  which  it 
gathers,  organizes,  and  interprets  these  facts.  Broadly 
speaking,  then,  the  psychologist's  subject  matter  concerns 
thinking,  feeling,  and  acting.  When  psychology  is  defined, 
as  often  occurs  today,  as  the  science  of  behavior,  it  is  to 
be  understood  that  the  term  behavior  includes  these  three 
processes.1  We  shall  try  in  this  book  to  point  out  what 
are  the  materials  of  which  intelligence  is  composed,  what 
the  conditions  under  which  it  arises,  what  the  purposes  for 
which  it  is  employed,  and  what  the  manner  in  which  con- 
duct is  controlled.  The  attempt  to  unravel  all  the  strands 
which  are  twisted  together  in  this  skein  of  life  will  take 
us  into  the  study  of  many  facts  seemingly  remote  from 
those  which  we  thus  set  out  to  explore. 

Physiological  and  Social  Conditions  of  Human  Ex- 
perience.— In  the  first  place,  all  life  is  built  upon  physical 
and  physiological  foundations.  It  is  quite  impossible  to 
understand  human  nature,  even  in  a  common-sense  way, 
without  a  knowledge  of  the  bodily  structure  of  the  human 
being.  Much  less  can  one  pretend  to  scientific  knowledge 
without  recourse  to  physiological  materials.  We  shall 
therefore  find  it  frequently  necessary  to  employ  informa- 

1 A  few  advocates  of  '  objective  psychology '  or  '  pure  behavior- 
ism' would  wholly  disregard  thinking  and  feeling,  devoting  their 
entire  attention  to  a  study  of  motor  activity. 


PROBLEMS  AND  METHODS  OF  PSYCHOLOGY     3 

tion  about  the  body,  and  particularly  about  the  brain  and 
nervous  system. 

Again,  all  life  to  some  extent,  and  especially  human 
life,  is  lived  among  social  surroundings.  It  is  idle  to  at- 
tempt to  understand  human  behavior  without  constant 
regard  to  these  social  relations.  Our  modern  science  has 
taught  us  to  see  all  contemporary  conditions  in  the  light 
of  their  evolution  from  the  past.  These  social  conditions 
quite  as  truly  as  those  of  a  physiological  kind  are  today 
interpreted  from  the  point  of  view  of  development  and 
adjustment.  Life  has  always  been  a  process  of  adapting 
the  organism  to  the  physical  conditions  of  climate  and 
food  supply  on  the  one  hand,  and  to  social  organization 
on  the  other.  The  conduct  of  man.  today  reflects  the  race- 
long  history  of  struggle  and  adjustment  in  each  of  these 
directions,  and  to  understand  any  piece  of  behavior  in- 
volves taking  into  account  to  some  extent  influences  which 
point  backward  to  this  illimitable  racial  past. 

Methods  of  Gathering  Facts  in  Psychology. — There  is 
in  progress  at  present  a  very  vigorous  controversy  as  to 
the  correct  method  in  psychology.  The  traditional  one 
upon  which  all  the  early  accomplishments  of  psychology 
rest  is  known  as  introspection.  It  consists  in  the  direct 
systematic  process  of  self-observation.  I  ask  myself  to 
recall  what  I  was  doing  yesterday  at  this  hour,  and  imme- 
diately after  bringing  into  mind  the  events  in  question,  I 
try  to  discern  and  describe  the  particular  manner  in  which 
the  occurrences  are  portrayed  in  my  thought.  I  may,  for 
example,  in  my  'mind's  eye'  see  myself  walking  to  my 
office.  Evidently  such  a  method  is  at  the  disposal  of 
anyone  who  chooses  to  employ  it.  It  is  purely  observa- 
tional, differing  from  the  usual  forms  of  external  observa- 


4      AN  INTRODUCTION  TO  PSYCHOLOGY 

tion  in  having  one's  own  internal  mental  operations  as  its 
object,  rather  than  the  facts  and  events  of  the  outside 
world. 

A  good  deal  of  mystery  has  at  times  been  attached  to 
this  introspective  process,  and  unmeasured  criticism  has 
been  directed  at  it,  ranging  all  the  way  from  a  denial  of 
its  possibility  on  the  ground  that  a  mental  state  cannot 
observe  itself  while  it  is  going  on,  down  to  the  less  sweep- 
ing but  more  pertinent  criticism,  that  the  method  is  prone 
to  many  forms  of  error  which  are  extremely  difficult  to 
control.  The  merits  of  this  controversy  can  hardly  be 
entered  upon  here.  Suffice  it  to  say  that  direct  observation 
of  the  kind  described,  i.e.,  of  mental  experiences  just  past, 
is  a  commonplace  of  everyday  life,  and  that,  carried  out 
carefully  and  systematically  by  many  individuals,  it  has 
resulted  in  the  accumulation  of  a  very  respectable  body 
of  knowledge  entirely  worthy  of  the  term  scientific. 

Over  against  introspection  or  subjective  observation,  is 
the  general  method  of  objective  observation,  which  is 
essentially  that  employed  in  all  the  physical  sciences.  The 
defenders  of  the  latter  urge  that  it  is  the  only  really 
scientific  method,  because  it  is  the  only  one  affording 
unequivocal  opportunity  for  verification  of  alleged  facts 
and  events  by  more  than  one  observer.  Needless  to  say, 
chemistry,  physics,  geology,  and  the  biological  sciences  in 
general  are  based  entirely  upon  this  method.  As  applied  to 
psychology,  it  necessarily  involves  the  attempt  to  use  the 
external  bodily  expressions  (e.g.,  gestures,  words,  facial 
movements,  etc.)  as  a  basis  for  the  understanding  of  be- 
havior, and  its  advocates  maintain  that  one  can  accurately 
describe  and  measure  the  significant  facts  of  mental 
activity  just  in  the  degree  in  which  one  can  determine  its 


PROBLEMS  AND  METHODS  OF  PSYCHOLOGY     5 

external  manifestations.  All  else,  they  say,  is  elusive,  and 
purely  subjective  and  incapable  of  scientific  treatment. 

The  fact  that  mental  states  do  ultimately  secure  expres- 
sion in  conduct  need  not  be  questioned;  nor  is  anyone 
likely  to  doubt  that  many  states  of  mind,  such  for  example 
as  anger  or  embarrassment,  may  be  reflected  immediately 
and  unequivocally  in  facial  expression.  But  there  is  also 
no  reason  to  call  in  question  the  fact  that  at  present,  at 
least,  our  ability  to  detect  accurately  the  external  expres- 
sions of  the  great  majority  of  our  mental  states  lags 
far  behind  our  ability  introspectively  to  describe  and 
analyze  them.  Who  can  say  from  observing  my  external 
appearance  whether  I  am  thinking  about  Napoleon  or 
Julius  Caesar?  It  seems,  therefore,  to  be  the  part  of 
common  sense  to  avoid  the  extremism  of  the  partisans  in 
this  controversy.  Let  us  recognize  that  wherever  possible, 
it  is  highly  desirable  to  make  use  of  the  bodily  expressions 
of  mental  states,  because  of  their  tangible  objective  char- 
acter; but  wherever  this  is  impossible,  as  is  at  present 
the  case  in  many  regions  of  mental  life,  let  us  rely  upon> 
trained  scientific  introspection. 

Scientific  Organization  of  Data. — It  should  be  clearly 
understood  that  both  of  these  methods  to  which  reference 
has  just  been  made  have  to  do  with  the  gathering  of  data, 
the  collecting  of  the  facts  of  intelligent  behavior.  This 
process  is  the  first  step  in  any  science,  but  it  is  only  the 
first.  There  then  remains  the  task  of  analyzing  and  organ- 
izing the  facts,  of  classifying  them  in  ways  which  will 
exhibit  their  relations  to  one  another  and  make  them  in- 
telligible in  their  entirety.  Moreover,  wherever  this  is 
practicable,  a  modern  science,  in  addition  to  trying  thus  to 
analyze  and  describe,  attempts  to  explain.  Analysis,  or- 


6       AN  INTRODUCTION  TO  PSYCHOLOGY 

ganization,  explanation,  the  ability  to  predict  events  be- 
cause of  the  knowledge  of  the  relations  of  cause  and  effect 
in  a  given  group  of  phenomena — these  are  the  character- 
istics of  every  established  natural  science. 

Experiment  in  Psychology. — Quite  the  most  important 
modern  advance  in  psychology  is  to  be  connected  with  the 
development,  in  the  middle  of  the  last  century,  of  the  ex- 
perimental movement.  Progress  in  the  other  natural 
sciences  has  been  rapid  directly  in  proportion  to  their 
development  of  experimental  technique.  An  experiment 
is  an  observation  made  under  conditions  of  control.  It 
gains  its  crucial  importance  from  the  fact  that  it  permits 
an  exact  repetition  of  conditions,  arid  thus  makes  possible 
verification  by  many  observers  of  whatever  facts  are  re- 
ported. It  had  always  been  supposed  that  mind  was  ex- 
cluded from  experimental  attack  because  the  necessary 
control  could  not  be  secured.  Thanks  largely  to  the  work 
of  Weber,  Fechner,  and  Wundt,  the  possibility  of  psycho- 
logical experiment  has  been  forever  put  beyond  the  pale 
of  doubt.  While  some  mental  processes  are  more  resistant 
than  others  to  experimental  approach,  there  is  hardly  any 
significant  group  of  mental  operations  which  has  been 
found  entirely  obdurate.  By  far  the  greater  portion  of  our 
mental  life  has  been  already  to  some  extent  explored  by 
experimental  methods. 

Experiment  has  shown  itself  fruitful  both  in  the  range 
of  introspection  and  in  that  of  objective  observation.  In 
the  one  case,  the  experimental  situation  is  so  devised  as  to 
assist  introspective  analysis,  and  to  permit  the  reinstate- 
ment time  after  time  of  substantially  the  same  mental 
conditions.  After-images  of  color  may  thus  be  studied 
by  repeating  the  stimulus  again  and  again.  In  the  case 


PROBLEMS  AND  METHODS  OF  PSYCHOLOGY     7 

of  direct  observation,  the  experiment  is  designed  to  elicit 
modes  of  behavior  which  can  be  observed  and  recorded  by 
the  experimenter.  The  promptness  of  a  movement  made 
in  response  to  a  sound,  for  example,  can  thus  be  determined 
by  time-measuring  apparatus.  Although  both  types  of 
observation  are  thus  involved  in  experimental  procedure, 
it  is  probably  fair  to  say  that  the  objective  type  is  tend- 
ing on  the  whole  to  displace  the  other. 

The  Different  Fields  of  Psychology. — In  the  present 
text  we  shall  be  chiefly  concerned  with  the  facts  involved 
in  ordinary  human  behavior.  This  field  is  commonly 
designated  general  psychology.  It  has  to  do  with  the 
typical  forms  of  behavior  characterizing  the  normal  adult. 
There  are,  however,  other  important  divisions  of  psychol- 
ogy which  we  shall  invade  from  time  to  time  in  order  to 
secure  useful  material.  The  mental  life  of  children  has 
been  rather  extensively  studied,  and  constitutes  a  reason- 
ably distinct  branch  of  investigation,  sometimes  called 
child  psychology,  sometimes  genetic  psychology.  Similarly 
the  study  of  mental  abnormalities  constitutes  another  sub- 
division generally  spoken  of  as  abnormal  psychology. 
Despite  the  fact  that  all  mental  life  of  human  beings  is 
lived  amid  social  surroundings,  and  that  it  is  quite  im- 
possible to  understand  human  behavior  without  regard  to 
influences  which  arise  from  these  relations,  it  has  been 
found  profitable  to  create  a  special  division  known  as 
social  psychology.  In  this  field  attention  is  particularly 
directed  to  a  study  of  the  explicitly  social  instincts  and 
attributes  of  the  mind,  and  to  an  analysis  of  the  mental  fac- 
tors in  social  organizations  and  institutions.  Race  psy- 
chology is  an  older  division  of  the  subject,  devoted  to  the 
attempt  to  ascertain  and  describe  those  peculiarities  of 


8      AN  INTRODUCTION  TO  PSYCHOLOGY 

temperament  and  behavior  which  ostensibly  characterize 
different  races.  Variational  psychology,  or  individual 
psychology,  concerns  itself  with  the  study  of  those  personal 
idiosyncrasies  of  temperament,  taste,  intellectual  capacity, 
etc.,  wliicli  mark  off  one  human  being  from  another.  Much 
of  the  most  interesting  and  significant  addition  to  our 
psychological  knowledge  has  in  recent  years  come  from 
the  study  of  animal  behavior.  To  this  field  is  generally 
applied  the  term  animal  psychology,  or  sometimes  the 
term  comparative  psychology. 

There  is  a  branch  of  psychology  known  as  pliysiological 
psychology  which  has  historically  grown  up  side  by  side 
with  experiment,  and  made  incessant  use  of  experimental 
procedure.  Strictly  speaking,  it  ought  perhaps  to  be  re- 
garded as  a  special  psychological  field.  It  is  often  spoken 
of  as  though  it  were  a  definite  method.  However  it  may 
be  classified,  it  consists  as  a  matter  of  fact  simply  in  the" 
attempt  systematically  to  study  mental  life  in  connection 
with  bodily  processes,  particularly  those  of  the  brain  and 
nervous  system.  We  shall  have  frequent  occasion  to  make 
use  of  its  materials. 

Psycliop'hysics  is  a  name  applied  to  a  branch  of  psy- 
chology developed  by  the  German  scientist,  Fechner.  It 
has  led  to  the  development  of  quantitative  psychology, 
which  is  concerned  with  the  attempt  to  measure  mental 
processes.  We  shall  have  relatively  little  to  do  with  this 
division  of  psychological  inquiry. 

Psychology  and  Other  Sciences. — In  advance  of  any 
detailed  knowledge  of  psychology,  it  is  hardly  profitable 
to  dwell  upon  its  relations  to  other  natural  sciences.  Suf- 
fice it  to  say  that  like  them,  it  has  historically  developed 
out  of  philosophy,  with  which  it  still  retains  rather  more 


PROBLEMS  AND  METHODS  OF  PSYCHOLOGY  9 

intimate  relations  than  do  those  sciences,  e.g.,  physics  and 
chemistry,  which  separated  themselves  from  the  parent 
(philosophical)  stem  at  an  earlier  time.  As  a  science 
psychology  may  fairly  claim  a  place  in  the  biological 
group,  because  its  subject  matter  is  life  in  certain  of  its 
expressions.  The  intimacy  of  the  relationship  is  in  a 
measure  attested  by  the  extent  to  which  psychology  con- 
ceives of  its  problems  in  evolutionary  terms  and  in  terms 
of  the  adjustment  of  the  organism  to  physical  and  social 
environment. 

Like  other  sciences,  psychology  has  both  a  pure  and  an 
applied  aspect.  In  its  applications,  it  stands  closely  re- 
lated to  education,  to  medicine,  to  jurisprudence,  and  to 
many  of  the  professional  and  practical  interests  of  life. 
These  applications  are  still  in  their  early  infancy,  and, 
although  extremely  interesting  and  valuable,  must  pre- 
sumably wait  for  any  approach  to  completeness  upon  a 
far  higher  development  of  the  pure  science.  It  is  fair  to 
add  that  they  are  themselves  making  genuine  and  im- 
portant contributions  to  this  pure  science. 


CHAPTER  II 
INHERITED  AND  ACQUIRED  BEHAVIOR 

It  will  perhaps  assist  us  if,  before  proceeding  to  a 
detailed  study  of  behavior,  we  pass  rapidly  in  review  some 
of  its  chief  forms.  This  will  give  us  a  rough  working  idea 
of  the  path  which  we  are  to  follow  in  our  more  exact 
analysis. 

Classification  of  the  Forms  of  Behavior. — For  prac- 
tical purposes  we  classify  behavior  in  many  different  ways. 
We  speak  of  it  as  good  or  bad,  as  kind  or  cruel,  as  thought- 
ful, stupid,  or  clever.  Evidently  such  divisions  are  de- 
signed to  mark  certain  moral  or  intellectual  qualities  which 
we  think  of  as  attaching  to  it.  Again,  we  may  classify 
from  the  point  of  view  of  the  special  kind  of  action  in- 
volved, e.g.,  work  or  play.  Walking,  speaking,  writing, 
skating,  golfing,  playing  the  piano,  are  all  modes  of  be- 
havior which  might  be  thus  distinguished. 

For  our  present  purposes  the  most  useful  classification 
and  the  one  which  we  should  keep  constantly  in  view, 
will  be  that  which  distinguishes  innate,  inherited,  and  in- 
stinctive forms  of  behavior  from  those  which  are  acquired, 
and  we  may  profitably  proceed  to  a  brief  description  of 
these  two  types. 

Instinctive  forms  of  action  are  such  as  the  nest-building 
activities  of  birds  and  insects,  the  seasonal  migrations  of 
fishes,  birds,  and  certain  mammals,  the  homing  habits  of 
pigeons  and  certain  marine  birds.  All  these  forms  of 

10 


INHERITED  AND  ACQUIRED  BEHAVIOR  11 

behavior  have  in  common  this  native  inborn  character  and 
their  fitness  to  achieve  certain  ends  necessary  to  the  preser- 
vation of  the  animal  or  the  species.  However  much  an 
animal  may  be  influenced  by  the  example  set  by  others 
of  its  kind,  it  is  quite  capable  of  executing  these  instinctive 
acts  wholly  without  tuition.  In  this  sense  they  are  entirely 
native,  and  not  learned. 

Although  popular  conception  does  not  always  recognize 
this  fact,  it  is  nevertheless  true  that  man  himself  possesses 
many  of  these  innate  forms  of  behavior.  The  trembling  of 
the  limbs,  the  blanching  of  the  face,  the  dryness  of  the 
mouth,  the  nausea  and  faintness  of  terror,  are  instinctive 
modes  of  behavior,  natural  to  every  child  and  carried  out 
quite  without  regard  to  either  precept  or  example.  Simi- 
larly the  clenching  of  the  fist  in  anger,  the  flushing  of  the 
skin  in  embarrassment,  the  shedding  of  tears  in  sorrow  or 
in  rage,  are  all  indigenous  modes  of  behavior,  inborn  in 
every  human  being.  These  activities,  like  those  cited  from 
animal  behavior,  are  all  designed  to  secure  some  end  essen- 
tial to  the  welfare  of  the  individual  or  the  race. 

Some  of  the  expressions  of  this  character  called  reflex 
acts  are  very  simple  and  are  called  forth  by  relatively 
simple  situations.  For  example,  the  contraction  of  the 
iris  in  the  presence  of  strong  light  is  a  relatively  simple 
muscular  movement  made  in  response  to  the  single  stim- 
ulus, light.  The  act  of  coughing  is  similarly  a  rather 
simple  muscular  response  to  irritation  in  the  throat.  Evi- 
dently the  incentive  to  the  instinctive  response  in  em- 
barrassment is  somewhat  more  complex.  It  involves  the 
apprehension  of  an  entire  situation,  instead  of  the  mere 
sensing  of  a  single  stimulation  like  light  or  irritation  of 
the  membranes  of  the  throat.  There  is  a  very  large  group 


12      AN  INTRODUCTION  TO  PSYCHOLOGY 

of  these  innate  forms  of  behavior  of  which  ordinarily  we 
are  wholly  unconscious.  All  the  great  life-sustaining 
bodily  operations  are  of  this  character.  The  beating  of 
the  heart  goes  on  for  the  most  part  entirely  without 
attracting  our  notice.  The  normal  processes  of  digestion 
are  similarly  unconscious.  Even  our  breathing  rarely  in- 
trudes itself  upon  attention. 

It  is  clear,  then,  upon  the  most  cursory  observation,  that 
the  human  being  comes  into  the  world  already  provided 
with  an  amazing  number  of  muscular  capacities  at  his 
disposal.  The  maintenance  of  life  is  from  the  very  first 
dependent  upon  the  proper  operation  of  these  inherited 
activities.  As  we  shall  later  see,  these  instinctive  traits 
constitute  the  foundation  upon  which  are  erected  all  the 
acquired  modes  of  behavior  which  we  shall  presently  study. 

Acquired  Behavior. — As  was  suggested  in  the  last  sen- 
tence, the  acquired  forms  of  behavior  rest  upon  the  in- 
stinctive types,  but  they  nevertheless  represent  quite  a 
different  order  of  affairs.  Nobody  is  born  with  the  ability 
forthwith  to  play  the  violin  or  to  use  the  typewriter.  Both 
achievements  require  long  practice  and  painstaking  effort. 
Speech  and  walking  both  have  an  instinctive  basis,  to  be 
sure,  but  both  require  an  extended  period  of  learning  be- 
fore they  are  at  all  perfect  or  complete.  Practically  all 
our  dexterities  and  acts  of  skill  are  of  this  character.  The 
putting  on  and  off  of  our  clothing,  the  manipulation  of 
the  common  utensils  of  daily  life,  our  social  deportment — 
expressive  of  the  conventional  etiquette  of  our  own  time, 
civilization,  and  set — our  enunciation,  our  professional 
habits,  even  in  large  measure  our  moral  and  religious  prac- 
tices and  beliefs,  are  of  this  acquired  character. 

As  we  sliall  discover  at  a  later  point  with  more  detail, 


INHERITED  AND  ACQUIRED  BEHAVIOR          13 

these  acquired  acts  have  all  become  established  as  the 
result  of  processes  in  which  the  mind  has  played  a  de- 
cidedly conspicuous  part.  In  this  regard  th^y  are  essen- 
tially different  .from  the  instinctive  modes  of  behavior. 
Of  these  latter  we  may  indeed  be  aware,  but  they  do  not 
owe  their  peculiar  form  to  any  thought  which  we  have 
accorded  them.  As  they  were  born  in  us,  so  they  appear. 
Obviously  the  execution  of  the  elaborate  conventional 
social  forms  peculiar  to  every  civilization  involves  careful 
tutelage  and  a  distinct  conscious  effort  of  acquirement. 
The  gestures  proper  to  the  greeting  of  a  lady  by  a  gentle- 
man in  Western  Europe  are  not  to  be  learned  without 
studious  effort.  Similarly  the  behavior  appropriate  to 
the  participant  in  a  ritualistic  service  involves  a  pro- 
longed apprenticeship  before  it  can  be  successfully 
mastered. 

Acquired  Acts  Become  Automatic. — All  these  illustra- 
tions suggest  what  is  a  fundamental  truth  later  to  be  more 
fully  explored,  i.e.,  that  many  acts  which  require  in  their 
early  stages  alert  conscious  supervision,  become  after  a 
time  essentially  automatic  and  take  care  of  themselves; 
that  is  to  say,  they  tend  to  simulate  the  instinctive  and 
innate  forms  of  behavior.  As  a  child,  it  requires  a  long 
and  tedious  course  of  training  to  master  the  niceties  of 
table  etiquette.  But  once  this  is  thoroughly  learned,  it 
practically  cares  for  itself;  and  the  same  thing  is  true  of 
all  the  other  acquired  types  of  behavior.  It  is  surprising 
to  find  how  large  a  part  of  the  behavior  of  one's  working 
day  is  of  this  automatized,  habitual  kind,  and  how  little 
of  it  involves  immediate,  thoughtful  supervision.  This  is 
but  another  way  of  saying  that  we  are  creatures  of  routine. 
It  involves,  however,  explicit  emphasis  upon  the  fact  often 


14      AN  INTRODUCTION  TO  PSYCHOLOGY 

unappreciated,  to-wit,  that  well-established  routine  de- 
mands very  little  active  mental  control. 

Instinctive  Behavior  in  Animals. — As  we  have  already 
intimated,  the  modern  evolutionary  conception  teaches  that 
those  types  of  reaction  which  are  effective  in  maintaining 
the  life  of  the  species  inevitably  tend  to  become  fixed  and 
to  be  perpetuated.  Nature,  it  is  said,  cares  nothing  for  the 
individual,  but  everything  for  the  species,  and  while  this 
is  no  doubt  an  overstatement  of  the  truth,  there  are  in- 
stances, particularly  in  insect  forms,  where  the  individual 
sacrifices  its  life  in  the  act  which  creates  the  new  genera- 
tion. It  is  certainly  true,  however,  that  no  mode  of  be- 
havior can  hope  for  survival  which  stands  opposed  to  the 
successful  maintenance  of  the  species.  The  great  body, 
then,  of  instinctive  forms  of  behavior  represents  types  of 
reaction  which  have  been  found  useful  in  the  past  for  the 
preservation  of  the  species.  Many  of  these,  in  the  nature 
of  the  case,  must  make  for  the  safeguarding  of  the  in- 
dividual as  well.  But  as  we  pass  upward  in  our  survey  of 
the  animal  forms  from  the  lower  to  the  higher,  we  find 
increasing  opportunities  for  individualistic  types  of  adjust- 
ment, and  it  is  in  this  region  of  adaptive  behavior  that 
we  encounter  the  group  of  actions  which  we  have  called 
acquired.  They,  too,  are  broadly  preservative  in  character, 
but  they  represent  the  region  of  unstable  and  incomplete 
adjustment.  The  individual  tries  out  for  himself  a  new 
line  of  action,  which  may  prove  a  success  or  a  failure. 

The  simplest  type  of  the  known  animals  is  represented 
by  amoeba.  The  amoeba  is  an  almost  structureless  speck 
of  jelly-like  protoplasm.  Under  the  microscope  it  can  be 
seen  to  consist  of  a  nucleus  surrounded  by  fluid  protoplasm. 
This  little  organism  secures  its  food  by  gradually  envelop- 


INHERITED  AND  ACQUIRED  BEHAVIOR  15s 

ing  it  with  its  liquid  surfaces.  If  it  be  attacked  by  strong 
acids,  or  similar  stimuli,  the  protoplasm  tends  to  flow 
away  from  the  source  of  attack.  Its  reactions  are  there- 
fore confined  to  these  simple  activities  of  approach  and 
retreat,  with  the  assimilation  of  food  and  the  rejection  of 
waste  products,  all  functions  of  this  one  simple  cell-like 
structure.  Evidently  the  scope  of  adjustive  activities  for 
such  a  creature  is  extremely  limited. 

Passing  to  a  much  higher  order  of  animal  life,  such  as 
is  represented  by  the  fishes,  we  find  again  that  the  main 
forms  of  adaptive  behavior  have  to  do  (1)  with  the  securing 
of  food;  (2)  with  the  escape  from  harmful  objects,  in- 
cluding both  animal  enemies  and  unfavorable  physical 
surroundings,  e.g.,  water  which  is  too  cold,  too  salt,  etc.; 
and  (3)  with  the  propagation  of  the  species.  In  the 
amoeba,  this  latter  function  is  brought  about  by  a  mere 
division  of  the  parent  cell.  In  addition  to  the  commoner 
modes  of  instinctive  expression  in  connection  with  the 
functions  which  we  have  listed,  fishes,  and  particularly 
birds,  display  the  most  amazing  migratory  adjustments, 
designed  to  afford  them  favorable  surroundings  for  the 
several  stages  of  their  life  cycle.  Practically  all  our  com- 
mon birds  migrate  annually  over  considerable  ranges  of 
territory,  and  some  of  them  journey  from  the  northern 
end  of  North  America  to  the  extreme  southern  end  of 
South  America. 

To  adjusting  activities  of  the  kinds  described,  the  more 
intelligent  mammals  (to  say  nothing  of  the  fishes  and 
birds)  add  many  types  of  gregarious  instincts,  which 
often  safeguard  the  members  of  the  group  from  their 
common  enemies.  In  some  cases  this  community  action 
has  an  aggressive  rather  than  a  merely  protective  char- 


16  AN  INTRODUCTION  TO  PSYCHOLOGY 

acter.  Wolves,  for  example,  hunt  in  packs,  as  do  some 
other  forms  of  wild  animals.  Buffalo,  deer,  and  domestic 
cattle  live  by  preference  in  herds  whose  numbers  to  some 
extent  protect  them  from  the  assaults  of  their  enemies. 
In  such  group  association  they  benefit  by  the  leadership 
of  the  stronger  and  more  intelligent  members  of  the  herd. 

Modification  of  Instinct  in  Man. — There  is  perhaps  no 
single  one  of  these  protective  forms  of  animal  behavior 
which  does  not  find  a  substantial  counterpart  in  the  be- 
havior of  man.  But  in  almost  every  case  a  form  of  be- 
havior, which  in  the  animals  is  primarily  instinctive,  is  in 
man  modified  through  various  kinds  of  acquired  adjust- 
ments and  often  perfected  to  a  degree  quite  surpassing 
the  animal  form.  Against  the  rigors  of  the  winter  the 
bear  retires  to  his  den  in  a  cave,  the  squirrel  to  his  nest 
in  the  tree,  but  man  builds  for  himself  the  most  elaborate 
of  artificial  shelters.  Where  the  bird  migrates  from  one 
end  of  the  continent  to  the  other  in  search  of  equable 
climate,  man  so  devises  his  house  that  it  may  be  cool  in 
summer  and  warm  in  winter.  In  other  words,  he  arti- 
ficially creates  his  own  preferred  climate.  The  animal' in 
his  search  for  a  livelihood  may  be  carried  by  conditions  of 
climate  over  many  degrees  of  latitude.  Man,  by  his  control 
over  agriculture  and  husbandry,  assures  himself  adequate 
food  at  his  very  door  the  year  around. 

More  striking  still  than  his  mastery  of  those  forms  of 
adjustment  which  relate  to  climate,  food  supply,  and  the 
general  characteristics  of  physical  nature,  is  the  extent 
to  which  his  instincts  have  been  evolved  to  meet  social 
conditions,  and  the  skill  with  which  of  his  own  intelli- 
gence he  has  learned  to  adapt  himself  to  the  demands  of 
social  circumstance.  If  one  disregard  the  appetites  of 


INHERITED  AND  ACQUIRED  BEHAVIOR  17 

hunger  and  thirst  and  the  instincts  connected  with  their 
satisfaction,  one  may  say  that  practically  all  the  remaining 
human  instincts  are  either  dominantly  or  exclusively  social 
in  their  import.  Anger,  hate,  fear,  love,  sorrow,  sympathy 
— the  list  may  be  drawn  out  almost  indefinitely — all  point 
to  social  forms  of  adjustment.  Arising  primarily  out  of 
the  great  group  of  instinctive  impulses,  but  with  modifica- 
tions introduced  at  various  points  by  reflective  intelligence, 
man  has  evolved  those  great  social  institutions  which  we 
designate  religion,  law,  custom,  government  and  the  state, 
the  family  and  the  church.  Even  commerce  and  industry, 
and  agriculture  in  all  its  forms,  represent  concretely  the 
modes  in  which  man  has  developed  his  processes  of  adjust- 
ment to  nature  and  to  his  fellow-man. 

These  illustrations  may  serve  to  suggest  how  wide  is  the 
range  in  animal  and  human  life  over  which  is  distributed 
the  process  of  adjustment,  and  how  manifold  are  the  forms 
with  which  it  clothes  itself.  It  remains  only  to  point  out 
that  while  much  of  this  adaptive  process  is  carried  out  by 
instinctive  and  often  unconscious  inherited  activities,  a 
large  part  of  it  is  the  result  of  the  play  of  thought  and 
feeling  flowing  out  into  acts  of  will,  constituting  in  their 
entirety  what  we  commonly  call  the  life  of  mind.  Our 
study  in  this  book  will  be  devoted  to  both  these  factors  in 
behavior,  i.e.,  instinctive  and  acquired  characteristics,  but 
more  particularly  to  the  last  named  portion  of  them. 


CHAPTER  III 
THE  NERVOUS  SYSTEM 

In  the  preceding  chapter,  attention  was  directed  to  cer- 
tain of  the  broad  typical  forms  of  organic  adjustment  to 
environment.  In  the  animal  kingdom  as  a  whole  probably 
the  great  majority  of  these  acts  are  reflex  in  character  and 
involve  little  or  no  direct  mental  supervision.  In  man, 
however,  the  types  of  adjustment  which  are  of  most  sig- 
nificance are  those  which  involve  the  definite  use  of  the 
mind.  Human  interest  is  naturally  centered  in  the  things 
which  we  choose  to  do,  or  not  to  do ;  the  things  which  pro- 
voke our  strong  feeling,  which  challenge  our  courage  or 
intelligence,  which  stimulate  our  ingenuity  and  test  our 
perseverance. 

To  even  a  superficial  survey  of  the  situation  it  must 
be  evident  that  the  mind  comes  into  possession  of  its 
knowledge  through  the  use  of  the  bodily  senses,  and  that 
in  turn  it  makes  itself  effective  through  its  control  of  the 
bodily  muscles.  Without  the  body  the  mind,  as  we  know 
it,  would  obviously  be  rather  helpless.  Modern  psychology 
has  therefore  been  disposed  to  learn  all  it  could  regarding 
those  portions  of  our  physical  structure  which  are  impor- 
tant for  our  mental  life.  Pursuant  to  this  tendency  we 
shall  now  undertake  to  gain  a  rough  working  conception 
of  the  nervous  system,  which  more  than  any  other  part  of 
our  bodily  frame  is  responsible  for  the  peculiarities  of 
mental  behavior.  We  shall  make  no  pretense  of  entering 

18 


THE  NERVOUS  SYSTEM  19 

in  any  detailed  way  upon  the  anatomy  or  physiology  of 
the  nervous  system.  We  shall,  however,  attempt  to  secure 
impressions,  which,  so  far  as  they  go,  will  be  accurate  and 
of  a  kind  to  render  us  constant  assistance  in  the  course  of 
our  study. 


FIG.  1. — Diagram  of  an  amoeba  greatly  magnified.  The  irregularly 
shaped  mass  of  protoplasm  is  shown  with  N,  its  nucleus,  and 
CV,  a  contractile  vacuole,  which  expands  and  contracts. 

The  biologists  tell  us  that  the  earliest  forms  of  life  were 
marine  plants  and  animals,  presumably  of  the  simplest 
possible  structure,  like  the  amoeba  (Fig.  1)  to  which  refer- 
ence was  made  in  a  previous  chapter.  In  animals  of  this 
type,  every  part  of  the  body  appears  to  be  sensitive  to 
stimulation.  Every  part  appears  capable  of  moving. 
There  is  no  definite  specialization  of  function.  But  as  we 
pass  to  higher  forms,  we  early  meet  with  the  beginnings  of 
that  process  which  in  the  higher  animals  has  resulted  in  the 
differentiation  of  functions  among  tissues.  To  some  are 
assigned  digestive  functions,  to  others  respiratory  func- 
tions, while  to  the  nerves  falls  the  function  of  transmitting 
excitement  from  one  part  of  the  organism  to  another. 
These  last  mentioned  tissues  have  appropriated  to  them- 
selves the  functions  of  control  which  accounts  for  their 
special  claim  upon  our  attention.  Figures  2  and  3  exhibit 
simple  forms  of  nervous  systems. 

Main  Subdivisions  of  the  Nervous  System. — There  are 


20 


AN  INTRODUCTION  TO  PSYCHOLOGY 


two  great  subdivisions  of  the  nerves  which  share  between 
them  the  important  duties  to  be  performed.  One,  the  so- 
called  'central'  system  cares  for  the  adjustment  of  the 


FIG.  2. — Nervous  system  of  a  starfish;  a,  central  nerve  ring  that 
surrounds  the  mouth;  6,  peripheral  nerves  of  the  arms.  (After 
Loeb.) 


8. ±. 


Fio.  3. — Dorsal  view  of  the  central  system  of  an  earthworm;  o, 
supraopsophageal  ganglion;  c,  commissure;  u.  sulxpsophageal 
ganglion;  8,  pharynx;  (!.  ganglion  of  the  ventral  cord.  (Aftev 
Loeb.) 


THE  NERVOUS  SYSTEM  21 

organism  to  the  outside  physical  world.  The  other,  the 
'autonomic'  system,  more  often  known  as  the  sympathetic 
system,  provides  for  the  proper  functioning  of  the  bodily 
organs  themselves.  The  central  system  connected  through 
one  set  of  terminals  with  the  various  sense  organs  such 
as  the  eyes  and  the  ears,  and  through  a  second  set  with 
the  muscles,  enables  the  organism  to  move  about  success- 
fully in  search  of  food  and  shelter  and  in  avoidance  of 
danger.  Meantime,  the  autonomic  system  keeps  the  diges- 
tion, respiration,  and  circulation  in  order,  oversees  many 
of  the  reflexes  and  more  particularly  the  processes  of 
assimilation  and  excretion,  and  in  general  assures  condi- 
tions of  physical  life  and  health.  The  central  system  may 
be  thought  of  as  the  provider,  the  autonomic  system  as  the 
housekeeper.  Of  course  their  functions  somewhat  overlap, 
for  the  two  are  intimately  connected,  and  neither  one  could 
get  on  without  the  other.  Mental  life  is  in  some  ways 
more  immediately  connected  with  the  activity  of  the  cen- 
tral system,  as  we  shall  presently  see,  but  it  is  also  related 
to  the  autonomic  system  in  many  important  particulars. 

Although  the  differences  in  these  two  great  divisions  of 
the  nervous  system  are  sufficient  to  make  it  wise  to  consider 
them  separately,  both  are  made  up  of  elementary  struc- 
tures known  as  neurones  which  we  must  briefly  describe. 

The  Neurone,  the  Element  of  the  Nervous  System. — 
The  fully  developed  neurone  resembles  ronghly  a  very 
slender  thread  with  a  knot  near  one  end  of  it,  the  end 
beyond  the  knot  being  frequently  frayed  out  into  a  num- 
ber of  brush-like  endings.  (See  Fig.  4.)  The  part  of 
the  neurone  corresponding  to  the  knot  is  the  so-called  cell 
body,  which  corresponds  roughly  to  the  seed  out  of  which 
a  plant  develops.  It  is  the  vital  center  of  the  neurone, 


22 


AN  INTRODUCTION  TO  PSYCHOLOGY 


and  if  it  be  destroyed,  the  remainder  of  the  structure  will 
die.  Like  the  plant  seed,  which  gives  off  certain  fibers 
that  develop  into  the  root  and  others  which  become  the 


FIG.  4. 

A,  B,  C,  D  represent  successive  stages  in  the  development  of  a  young 
neurone.  "  E  represents  a  fully  developed  pyramidal  cell  from 
the  cortex  of  the  cerebrum,  showing  the  granular  and  nuclear 
character  of  the  cell  body.  D  and  E  both  show  the  differ- 
ences in  the  appearance  of  axones,  ax,  and  dendrites,  d,  and  F 
exhibits  the  typical  structure  of  a  fully  developed  nerve  fiber 
of  the  periphery,  etc,  the  axis  cylinder,  or  true  nerve,  of  the 
axone;  m,  the  thick  pulpy  medullary  sheath;  p,  the  thin  mem- 
branous primitive  sheath,  both  the  sheaths  protective  and  prob- 
ably nutritive;  G,  shows  a  cross-section  of  such  a  nerve  trunk. 
H  exhibits  segments  of  the  unmedullated  fibers  of  the  sym- 
pathetic system.  (Modified  from  Cajal  and  Toldt. ) 

stalk,  the  cell  body  of  the  neurone  usually  gives  off  two 
forms  of  minute  filaments.  These  possess  as  a  rule  certain 
differences  in  appearance  shown  in  Fig.4D,E.  The  neurones 


THE  NERVOUS  SYSTEM  23 

vary  enormously  in  their  dimensions.  Some  of  them  may 
be  two  or  more  feet  in  length.  Such  are  the  fibers  which 
extend  from  the  base  of  the  spinal  cord  into  the  sole  of 
the  foot.  Others  (examples  occur  in  the  brain)  are  only 
a  fraction  of  a  millimeter  in  length,  and  a  cross-section  of 
any  of  them  short  or  long  would  ordinarily  require  a 
microscope  to  be  clearly  seen.  The  nerves  which  are 
sometimes  exposed  to  view  as  the  result  of  an  injury  or 
an  operation  are  in  reality  great  bundles  of  these  little 
fibrils,  .brought  together  like  the  wires  of  a  telephone 
circuit  in  a  cable,  such  as  one  may  often  see  upon  our 
streets. 

Classification  of  Neurones. — For  our  purposes  the 
neurones  may  conveniently  be  divided  into  three  great 
groups:  (1)  those  which  carry  impulses  in  toward  the 
central  system.  These  are  called  sensory  neurones  or  re- 
ceptors, because  they  receive  sensory  stimulations.  (2) 
The  neurones  which  carry  impulses  from  the  central  sys- 
tem out  to  the  muscles  or  glands.  These  may  be  called 
effectors,  because  they  produce  specific  effects  of  adjust- 
ment. Effectors  entering  muscles  are  frequently  desig- 
nated motor  nerves.  (3)  Those  which  connect  the  first 
group  with  the  second.  These  may  be  called  central  ad- 
justers, or  connectors.  Although  the  forms  of  the  neurones 
differ  somewhat  when  seen  under  the  microscope,  accord- 
ing to  the  particular  portion  of  the  nervous  system  from 
which  they  come,  they  are  alike  in  the  fact  that,  so  far 
as  is  known  in  the  higher  organisms  at  least,  normal 
nervous  impulses  always  flow  over  them  in  one  and  only 
one  direction.  This  means  that  a  neurone  which  cus- 
tomarily conveys  impulses  from  a  sense  organ  to  the 
brain  or  cord  can  never  conduct  an  impulse  backward  from 


24  '  AN  INTRODUCTION  TO  PSYCHOLOGY 

the  cord  or  brain  to  the  sense  organ.  Similarly  the  effector, 
which  carries  impulses  out  toward  the  muscles,  can  never 
convey  an  impulse  back  from  the  muscle  to  the  center. 
We  may  express  the  situation  in  magnetic  terms  by  saying 
that  the  nervous  system  is  polarized.  Its  currents  flow 
only  in  one  direction. 

*  Each  sensory  receptor  terminates  at  or  beneath  the  sur- 
face of  the  body  in  contact  with  some  kind  of  specialized 
tissue  so  organized  as  to  be  sensitive  to  a  particular  form 
of  physical  or  chemical  stimulus.  Thus  the  optic  fibers 
terminate  in  contact  with  the  rods  and  cones  of  the  retina, 
of  which  we  shall  learn  more  in  a  later  chapter.  These 
microscopic  structures  are  sensitive  to  light.  When  they 
are  stimulated,  changes  occur  in  them  (probably  of  electro- 
chemical character)  that  set  up  impulses  in  the  nerve  fibers, 
which  then  transmit  the  nervous  excitation  to  the  brain. 
The  auditory  neurones  terminate  similarly  in  the  internal 
ear,  about  the  bases  of  minute  structures  known  as  hair 
cells,  which  are  thrown  into  vibration  when  sounds  fall 
upon  the  ear.  Again,  the  nerves  distributed  to  the  skin 
come  to  an  end  in  contact  \vith  minute  structures  in  the 
dermis,  which  are  sensitive  to  contact,  or  to  heat,  or  to  cold. 
One  form  of  cutaneous  neurone,  i.e.,  the  so-called  "pain 
nerve"  has  not  thus  far  been  found  to  have  any  special 
terminal  organ.  But  this  is  an  exception  to  which  we  shall 
return  in  another  chapter. 

Certain  effectors  or  motor  nerves  leading  out  from  the 
central  system  terminate  in  the  surfaces  of  the  muscles. 
When  a  nervous  impulse  travels  down  one  of  these  nerves, 
it  causes  the  muscle  with  which  it  is  connected  to  con- 
tract, and  this  in  turn  brings  about  a  movement  of  the 
part  of  the  body  in  which  the  muscle  is  found.  When  the 


THE  NERVOUS  SYSTEM 


25 


reader  raises  his  hand  to  turn  the  page  of  this  book,  the 
movement  is  brought  about  by  just  such  a  nervous  impulse 
originating  in  the  brain  and  passing  from  that  point 
through  the  spinal  cord  and  over  motor  nerves  into  the 
muscles  of  the  hand  and  arm.  Similarly,  an  impulse  may 


M 


FIG.  5. — Diagram  to  illustrate  synapsis  of  arborization  of  axone  of 
a  sensory  receptor  from  the  skin,  8K,  with  dendritic  terminals 
of  central  system  neurones,  1,  2.  The  synapses  of  motor  axones, 
3,  4,  with  dendrites  of  an  effector  terminating  in  a  muscle,  M, 
are  similarly  shown. 

be  sent  out  into  a  gland,  which  is  then  thrown  into  activity, 
whether  .of  secretion  or  excretion.  A  cinder  in  the  eye 
will  thus  occasion  a  flow  of  tears.  As  we  shall  see  in  more 
detail  at  a  later  point,  certain  of  the  glands  are  excited 
to  great  activity  by  the  more  powerful  emotions. 

The  central  adjuster  neurones  are  located  within  the  great 


26      AN  INTRODUCTION  TO  PSYCHOLOGY 

masses  of  the  spinal  cord  and  the  brain,  and  we  shall  give 
a  brief  description  of  them  presently. 

Neurones  come  into  connection  with  one  another  at 
the  terminal  points  of  their  fibers  as  shown  in  Fig.  5. 
Whether  they  actually  touch  or  not  is  unknown.  At  all 
events  they  are  very  close  to  one  another.  Such  junction 
points  are  called  synapses  and  are  of  very  great  impor- 
tance in  the  operation  of  the  nerves.  Like  the  nerve  fibers 
themselves,  they  are  seemingly  polarized,  so  that  impulses 
can  pass  in  only  one  direction. 

The  Sensory-Motor  Pattern  of  the  Nervous  System. — 
The  fundamental  pattern  in  accordance  with  which  the 
nervous  system  is  built  up  involves,  as  we  have  already 
indicated,  (1)  a  system  of  receptors,  (2)  a  system  of 
effectors,  and  (3)  a  system  of  interconnecting  neurones  by 
means  of  which  the  various  muscles  are  brought  into  com- 
munication with  the  various  sense  organs,  so  that  (4)  a 
stimulation  of  any  one  of  the  latter  may  occasion  a  move- 
ment of  any  one  of  the  former.  (See  Pig.  6B,  C.)  In  the 
lower  types  of  organism,  these  connections  are  relatively 
fixed  and  rigid,  and  in  the  first  instance  the  muscles 
are  innervated  by  impulses  which  arise  from  sense  organs 
lying  in  the  same  region  of  the  body.  This  arrangement 
is  represented  diagrammatically  in  the  accompanying 
sketch.  (Fig.  6 A.)  The  use  of  such  an  arc,  or  circuit,  as 
it  is  called,  would  be  illustrated  by  the  reflex  withdrawal 
of  the  hand  when  it  is  cut  or  bruised  or  burned.  In  such 
a  case  the  nervous  impulse  passes  up  the  receptors  into  the 
spinal  cord,  where  it  is  turned  about  and  sent  over  the 
effectors  into  the  muscles  of  the  hand  and  arm. 

The  brain  and  the  cord  in  their  entirety  represent  very 
elaborate  complications  of  this  basic  pattern,  of  such  a 


THE  NERVOUS  SYSTEM  27 

kind  as  to  permit  almost  every  conceivable  combination  of 
relations  between  sense  organs  and  muscles.  The  hand 
may  be  moved  not  only  in  response  to  stimulations  from 
the  skin  of  its  own  surfaces,  but  also  in  response  to  stimu- 


FIG.  6. 

A  exhibits  pattern  of  the  simplest  sensory-motor  arc,  where  a  peri- 
pheral stimulus  immediately  elicits  a  movement  of  the  region 
stimulated;  1  is  the  receptor,  2  the  connector  and  3  the  effector. 
In  some  very  simple  reflexes  1  may  be  directly  conjoined  with 
3,  omitting  2.  The  diagram  also  suggests  in  the  dotted  line  a 
very  important  fact,  i.e.,  that  the  contraction  of  M  sets  up  kin- 
aesthetic  sensory  impulses  which  pass  into  the  nervous  centers, 
opening  a  new  circuit,  and  in  turn,  perhaps,  eliciting  other 
movements. 

B  illustrates  how  two  sets  of  muscles  may  be  innervated  from  either 
of  two  sets  of  sense  organs.  The  same  pattern  can  be  elaborated 
to  include  all  the  senses  and  all  the  muscles.  It  is  purely 
diagrammatic.  The  actual  paths  would  involve  many  more 
neurones. 

C  illustrates  rudely  three  levels  of  circuits  in  the  nervous  system. 
The  lowest,  r,  is  purely  reflex  and  does  not  necessarily  involve 
consciousness.  It  is  typified  by  the  conditions  in  the  spinal 
cord,  medulla,  and  lower  brain  centers.  These  neurone  circuits 
are  congenitally  open.  The  second,  p,  represents  the  level  of 
crude  perceptual  reactions  and  mere  sensory-motor  learning, 
such  as  most  animals  exhibit.  The  sensory-motor  regions  of 
the  cerebrum  are  presumably  represented  in  these  circuits. 
The  ideational  circuits  are  represented  by  i  and  involve  con- 
scious memory,  imagination,  reflective  thought  and  rational  in- 
ference. In  addition  to  the  sensory-motor  zones,  this  circuit 
makes  use  of  the  most  highly  developed  regions  of  the  cerebral 
cortex,  i.e.,  the  frontal,  parietal  and  other  association  areas. 
See  the  later  part  of  this  chapter. 


28      AN  INTRODUCTION  TO  PSYCHOLOGY 

lations  from  other  cutaneous  regions,  as  when  one  lifts  the 
right  hand  to  remove  some  object  pressing  upon  the  left 
hand,  or  some  other  body  surface.  Similarly,  it  may  be 
moved  in  response  to  a  sound  which  is  heard,  or  an  object 
seen,  etc.  As  we  have  already  observed,  many  of  these 
muscular  movements  are  inherited,  and  are,  upon  the 
appropriate  stimulation,  executed  without  previous  train- 
ing. The  simplest  of  such  acts  are  called  reflexes  (e.g., 
coughing,  sneezing,  crying).  Many  others,  however,  and 
among  them  the  acts  of  most  psychological  interest,  are  in 
part  or  wholly  acquired,  that  is,  learned.  The  flexible 
organization  of  the  central  adjuster  neurones  renders  such 
learning  possible,  because  it  permits  the  conjoining  of  any 
receptor  with  any  effector.  If  the  hand,  for  example,  could 
not  be  controlled  by  stimulations  from  the  eye  but  only 
by  those  from  the  skin,  it  would  be  extremely  difficult  to 
learn  to  write,  cr  to  use  the  typewriter,  or  to  perform  any 
of  the  other  acts  of  skill  in  which  the  hand  is  largely  di- 
rected by  vision.  Moreover,  in  man— in  contrast  to  the 
conditions  found  in  many  animals — arrangements  exist  for 
the  control  of  the  muscles  from  ideational,  as  well  as  from 
sensorial,  centers. 

If  the  reader  will  bear  constantly  in  mind  this  notion 
of  the  central  nervous  system  as  made  up  of  elaborate  com- 
binations of  sensory  and  motor  elements,  it  will  be  found 
to  throw  light  upon  the  general  anatomical  situation,  which 
we  may  now  attempt  to  describe  in  a  little  more  detail. 

Main  Divisions  of  the  Central  System. — The  central 
nervous  system  comprises  the  brain,  the  spinal  cord,  and 
the  two  great  groups  of  receptor  and  effector  neurones. 
(See  Figs.  7  and  8.)  The  brain  and  cord  are  nothing  but 
masses  of  neurones  gathered  together  and  held  in  place  partly 


THE  NERVOUS  SYSTEM 


29 


Cor 


S, 


FIGS.  7  and  8. — Fig.  7  at  the  left  shows  the  general  relations  of  tli 
central   nervous   system   to  the   bones  of  the  skull   and   spine. 


30      AN  INTRODUCTION  TO  PSYCHOLOGY 

by  the  veins  and  arteries,  partly  by  a  connective  support- 
ing tissue  called  neuroglia,  and  partly  by  a  series  of 
strong,  firm  membranes  enclosing  these  great  masses  as 
though  within  the  walls  of  an  irregularly  shaped  bag.  In 
the  case  of  the  brain,  these  containing  membranes  are 
attached  to  the  bones  of  the  skull,  and  in  the  case  of  the 
cord  are  supported  within  the  central  canal  of  the  spinal 
vertebrae. 

Figure  9  illustrates  in  a  rude  way  the  essential  features 
in  the  structure  of  the  spinal  cord.  The  outer  regions  of 
the  cord  near  its  surfaces  are  exclusively  occupied  by  nerve 
fibers  which  carry  impulses  to  and  fro.  The  inner  regions, 
on  the  other  hand,  are  largely  composed  of  cell  bodies, 
which,  as  we  earlier  learned,  are  the  centers  from  which 
the  nerve  fibers  spring.  The  two  great  functions  of  the 
cord  are  at  once  suggested  by  its  anatomical  appearance. 
It  is  first  a  great  reflex  center,  receiving  impulses  from 
sense  organs,  and  immediately  sending  them  out  again  into 
muscles  and  glands.  If  the  sole  of  the  foot  be  tickled  or 


Fig.  8  at  the  right  displays  the  general  contours  of  the  central 
system  as  seen  from  in  front.  The  great  ganglionated  cord  of 
the  sympathetic  system  is  shown  attached  to  one  side  of  the 
spinal  nerves;  the  other  side  has  been  cut  away.  Cer.,  the 
cerebral  hemispheres;  0,  the  olfactory  centers;  P,  the  pons 
Varolii;  M,  the  medulla  oblongata;  (76.,  the  cerebellum;  Sp.  C., 
the  spinal  cord;  /,  the  olfactory  nerve;  //,  the  optic  nerve;  ///, 
the  oculo-motor  nerve,  connected  like  IV,  the  trochlear  nerve 
and  VI,  the  abducens  nerve,  with  the  muscles  of  the  eye;  V, 
trigcminus,  made  up  in  part  of  sensory  fibers  coming  from  the 
face  and  scalp,  partly  of  motor  fibers  supplying  neighboring 
regions;  VII,  the  facial  nerve,  similarly  in  part  giving  sensory 
fibers  to  the  face,  tongue  and  neck,  in  part  made  up  of  motor 
fibers;  VIII,  the  auditory  nerve;  IX,  glossopharyngeal  nerve, 
giving  both  sensory  and  motor  fibers  to  throat  and  tongue;  X, 
the  vagus  nerve,  both  sensory  and  motor,  very  complex  distribu- 
tion, chiefly  to  heart,  stomach  and  other  viscera;  XI,  spinal 
accessory,  connected  with  sympathetic  system;  XII,  hypo- 
glossal  nerve,  motor  fibers  to  tongue. 


THE  NERVOUS  SYSTEM 


31 


pricked,  there  is  at  once  a  reflex  jerk  of  the  foot  for  which 
the  spinal  cord  is  responsible ;  and  this  is  typical  of  other 
forms  of  reflex  action  under  the  control  of  the  cord.  In 
the  second  place,  it  is  the  great  channel  through  which 
impulses  from  many  receptors  flow  upward  into  the  brain, 


Anterior  root 


Central  motor  pathway 
Motor  ganglion  cell 


Motor  nerve 
ending  in  muscle 


Sensory  fiber 


Peripheral 
ending  sensory 
nerve 


Posterior  root 


Ascend  ing  and 
— _  descending  branch  of 
,-'  sensory  fiber 


Sensory  collateral 


Cell  and  fiber  of 
lateral  column 


olar  cell  of  spinal  ganglion 


FIG.  9. — Schematic  representation  of  the  connection  of  sensory  and 
motor  nerves  with  the  spinal  cord,  and  their  synapses  with  one 
another  inside  the  gray  matter  of  the  cord.  The  cross  section 
at  the  top  of  the  diagram  exhibits  clearly  the  difference  between 
the  white  marginal  fibrous  material  and  the  H-shaped  center 
of  gray  cellular  matter.  Reference  to  Figure  9  will  show  how 
the  combined  sensory-motor  strands  make  their  exit  between 
the  vertebrae. 

and  through  which  *these  impulses  are  returned  from  the 
brain  to  the  muscles.  The  outer  regions  of  the  cord  are 
those  principally  engaged  in  this  conductive  function. 
The  central  regions  contain  the  arrangements  whereby  the 
reflexes  are  brought  about,  i.e.,  the  contact  of  terminals 


32 


AN  INTRODUCTION  TO  PSYCHOLOGY 


from  the  receptors  with  terminals  of  the  effectors.  There 
are  similar  synapses  of  central  adjusters,  or  connectors, 
with  effectors.  Thus  the  motor  neurones  from  the  cerebrum 


OB 


OB 


RFC 


SC 


OL 


FIG.  10. — The  brain  seen  from  below.  PL,  the  frontal  lobes  of  the 
cerebral  hemispheres;  OB,  bulb  of  olfactory  nerve;  TL,  tem- 
poral lobes;  ON,  optic  nerve;  HO,  hippocampal  gyrus;  LPC, 
RFC,  left  and  right  peduncles,  or  legs,  of  the  brain,  great  masses 
of  fibers;  P,  pons  Varolii,  or  bridge,  great  band  of  fibers  con- 
necting the  two  sides  of  the  cerebellum;  MO,  medulla  oblongata; 
C,  cerebellum;  SC,  spinal  cord;  OL,  occipital  lobes.  (Modified 
from  Edinger. ) 

discharge  over  neurones  which  join  them  in  the  gray  matter 
of  the  spinal  eord. 
It  will,  no  doubt,  be  understood  that  the  upper  regions 


THE  NERVOUS  SYSTEM 


33 


of  the  cord  are  connected  with  the  upper  portions  of  the 
body,  and  the  lower  portions  with  the  lower  parts  of  the 
trunk  and  with  the  legs.  This  is  true  both  as  regards  the 
receptors  and  the  effectors.  These  are  both  gathered  up 
into  bundles  which  are  given  off  from  the  cord  in  pairs 
between  the  vertebrae.  As  shown  in  Fig.  9,  the  sensory  or 
receptor  group  enters  the  posterior  lateral  part  of  the  cord, 


OAf 


SC 


FIG.  11. — Diagrammatic  sketch  of  a  vertical  section  from  front  to 
back  through  the  central  regions  of  the  hemispheres,  cerebellum, 
brain  stem  and  cord.  CH,  cerebral  hemispheres;  CQ,  corpora 
quadrigemina ;  Cb,  cerebellum;  SC,  the  spinal  cord;  P,  pons 
Varolii;  T,  optic  thalamus;  ON,  optic  nerve.  The  sketch  indi- 
cates a  few  of  the  neurone  paths.  (Modified  from  Edinger.) 

the  motor  or  effector  group  is  given  off  on  the  anterior 
lateral  surface. 

At  the  point  where  the  cord  leaves  the  spinal  vertebrae 
to  enter  the  skull,  it  broadens  out  to  form  the  medulla 
dblongata.  This  structure  contains  a  number  of  extremely 
important  reflex  centers.  For  example,  here  are  located 


34 


AN  INTRODUCTION  TO  PSYCHOLOGY 


the  nerve  centers  primarily  responsible  for  the  control  of 
breathing.  The  rate  of  the  heart  beat  may  also  be  altered 
by  impulses  from  the  medulla.  Furthermore,  the  distribu- 
tion of  the  blood  in  the  body,  e.g.,  as  between  the  skin  and 
the  viscera,  is  controlled  from  this  region. 


GB 


M 


SO 


FIG.  12. — A  sketch  to  indicate  the  general  location  of  the  optic 
thalami.  The  cerebral  hemispheres  have  been  entirely  removed 
and  all  but  a  portion  of  the  right  side  of  the  cerebellum.  T, 
optic  thalami.  Figures  7,  8,  10  and  11  should  be  compared 
with  this.  OB,  geniculate  bodies;  CQ,  corpora  quadrigemina; 
P,  a  segment  of  the  pons  Varolii;  C,  cerebellum;  M,  medulla 
oblongata;  8C,  spinal  cord.  (After  Edinger. ) 

As  we  pass  upward,  we  encounter  a  number  of  other 
conspicuous  parts  of  the  brain,  such  as  the  cerebellum,  the 
pons  or  bridge,  the  corpora  quadrigemina,  the  optic 
thalami,  etc.  (See  Figs.  10,  11,  12.)  The  functions  of 
many  of  these  organs  are  still  obscure,  and  it  will  be  un- 
profitable for  us  to  give  them  consideration,  with  one  or 


THE  NERVOUS  SYSTEM  35 

two  exceptions.  In  every  case,  however,  it  is  to  be  under- 
stood that  they  consist  of  masses  of  cell  bodies  and  fibers 
similar  to  those  in  the  spinal  cord  and  medulla. 

The  cerebellum,  whatever  other  part  it  may  play,  is 
quite  certainly  responsible  for  the  orderly  control  of  our 
muscular  movements,  particularly  such  as  are  involved  in 
our  maintenance  of  bodily  balance.  As  we  walk,  for  ex- 
ample, it  is  clearly  essential,  if  our  gait  is  to  be  effective, 
that  each  of  the  muscles  controlling  the  foot,  knee,  and 
hip  should  contract  at  just  the  right  time  and  to  just  the 
right  extent.  Were  the  muscles  controlling  the  knee  to 
contract  too  soon  or  too  violently,  one's  balance  would 
obviously  be  disturbed,  and  a  well-ordered  pace  would  be 
impossible.  The  cerebellum  receives  from  moment  to  mo- 
ment sensory  reports  of  the  bodily  position,  and  orders 
the  motor  discharges  to  meet  the  requirements. 

In  general  those  parts  of  the  central  system  lying  below 
the  cerebral  hemispheres  have  to  do  with  our  reflex  and 
instinctive  behavior.  They  operate  under  the  general 
supervision  of  the  cerebrum,  a  fact  which  is  shown  by  the 
exaggeration  of  their  activities  when  the  hemispheres  are 
surgically  destroyed,  as  may  happen  in  certain  animals 
without  causing  death.  The  acquired  acts  depend  more 
definitely  upon  the  cerebrum. 

The  Cerebral  Hemispheres. — Omitting  for  a  few  mo- 
ments some  brief  comments  on  the  thalami,  this  brings  us 
then  to  that  part  of  the  brain  most  intimately  connected 
with  mental  life,  to-wit,  the  cerebral  hemispheres.  This  is 
the  organ  whose  great  size,  relative  to  the  other  parts  of 
the  brain,  distinguishes  the  nervous  system  of  man  and 
the  higher  animals  like  the  apes,  from  those  lower  down 
in  the  scale.  In  man,  too,  the  association  regions,  to  be 


36      AN  INTRODUCTION  TO  PSYCHOLOGY 

FIGS.  13  and  14. 

FIG.  13  shows  the  lateral  surfaces  of  the  right  hemisphere  of  the 
cerebrum,  figure  14  the  inner  mesial  surface  of  the  left  hemisphere. 
The  latter  section  is  made  through  the  corpus  callosum,  the  right 
hemisphere  being  removed.  Surfaces  covered  by  colored  dots  are 
the  so-called  motor  regions,  whence  originate  neurones  in  control 
of  voluntary  muscles.  There  are  some  small  and  relatively  unim- 
portant motor  areas  elsewhere  in  the  cortex,  e.g.,  in  the  occipital 
region  some  connected  with  vision.  The  sensory  areas,  the  receiving 
stations  for  sensory  impulses  from  the  periphery,  are  indicated  by 
black  dots.  The  regions  most  heavily  dotted,  both  sensory  and  motor, 
are  those  most  indispensable  for  the  given  function.  The  areas  less 
heavily  dotted  are  those  which  are  less  uniformly  employed  in  the 
exercise  of  the  function,  or  whose  derangement  affects  the  secondary 
or  more  complex  use  of  the  function.  For  example,  visual  images 
and  ideas  may  be  disturbed  by  injuries  in  the  visual  areas  which 
do  not  seriously  impair  crude  sensations  of  sight.  The  areas  free 
from  dots  are  the  association  regions,  which  Flechsig  has  divided 
into  a  number  of  subordinate  districts. 

R,  Rolando,  a  deep  fissure  separating  the  convolutions  of  M,  the 
principal  motor  regions,  from  B,  the  somasthetic  sensory  regions  for 
bodily  sense  impressions,  e.g.,  touch,  temperature,  kin«sthetic.  The 
right  half  of  the  body  is  in  general  controlled  by  the  left  side  of 
the  cerebral  cortex  as  regards  both  sensory  and  motor  processes,  and 
vice  versa.  In  the  motor-somsesthetic  area  specific  parts  of  the  body 
are  controlled  by  special  regions  of  the  cortex,  e.g.,  the  muscles  of 
the  legs  are  controlled  from  centers  lying  just  under  the  letter  AI  in 
"Figure  13.  The  speech  muscles  are  controlled  from  regions  near  the 
lower  edge  of  the  motor  convolution  in  this  figure.  Injury  to  the  left 
side  (in  right-handed  people)  is  likely  to  produce  motor  aphasia, 
i.e.,  inability  to  articulate  correctly.  The  patient  is  not  paralyzed, 
but  cannot  pronounce  his  words  correctly.  A  center  somewhat 
higher  up  controls  hand-writing.  These  relations  are  all  suggested 
in  Figure  19.  V,  visual  center.  Injury  here  may  produce  various 
effects  depending  on  its  location  and  extent.  Total  blindness  to 
half  the  field  of  view,  inability  to  read  or  understand  what  is  seen, 
without  actually  being  blind,  are  all  found  as  symptoms  of  occipital 
lobe  injuries.  II,  auditory  center.  In  right-handed  persons  injury 
to  the  left  hemisphere  in  this  region  is  likely  to  result  in  sensory 
aphasia,  inability  to  understand  words  when  heard.  Complete 
destruction  of  the  region  on  both  sides  is  said  to  be  followed  by  total 
deafness.  0,  the  olfactory  center  which  exends  in  a  great  loop  up 
over  the  corpus  callosum.  The  extent  of  the  area  is  quite  uncertain 
and  the  drawing  simply  suggests  the  facts  at  present  generally  recog- 
nized. The  confinement  of  motor  and  somaesthetic  areas  to  the  region 
above  the  limbic  lobe  of  the  corpus  callosum  is  also  tentative,  al- 
though asserted  by  competent  investigators.  O.B.,  the  olfactory 
bulb;  O.T.,  the  olfactory  tract;  O.T.A.,  occipito-temporal  association 
area;  A.P.,  parietal  association  area,  continuous  with  the  occipito- 
temporal  association  area;  A.F.,  frontal  association  area;  /.,  the 
Island  of  Reil,  another  association  area  to  show  which  the  cortical 
surfaces  just  above  the  fissure  of  Sylvius  have  been  lifted  up;  C.C., 
the  corpus  callosum,  a  great  band  of  fibers  connecting  the  two  sides 
of  the  hemispheres. 


AP__ 


OTA 


FIG.  13 


AP 


— AF 


0 


FIG.  14 


THE  NERVOUS  SYSTEM 


37 


explained  in  a  moment,  are  relatively  much  larger  than  in 
most  animals.  However,  man  apparently  owes  his  superior 
intelligence  more  to  the  organization  of  his  brain  than  to 
its  size.  As  is  indicated  in  Figs.  8,  13  and  14,1  the  hemi- 


ROMC 


SOC 


FIG.  15. — Diagram  to  illustrate  the  shortest  pathways  from  sense 
organs  to  cortex,  and  from  cortex  to  muscles.  No  doubt  the 
actual  pathways  are  generally  more  complex. 

Taking  the  skin  nerves  as  an  example  of  the  sensory  pathways  we 
find,  first,  an  end-organ  in  the  skin,  then  a  cell  in  the  ganglion 
outside  the  spinal  cord  sending  a  fiber  out  to  the  end-organ 
and  another  to  the  cord.  The  next  neurone  has  its  cell-body 
in  the  medulla  and  communicates  with  one  located  in  the 
thalamic  region,  which  in  turn  communicates  with  a  cell  in  the 
cerebral  cortex,  thus  completing  the  chain  from  skin  to  cere- 
brum. Passing  downward  from  motor  centers  we  find  a  long 
fiber  extending  through  the  so-called  pyramidal  pathway  (of 
which  the  principal  crossed  tract  is  shown  in  Fig.  18)  and 
terminating  somewhere  in  the  gray  matter  of  the  anterior  horn 
of  the  spinal  cord,  where  it  communicates  with  another  neurone 
which  sends  out  a  fiber  to  a  muscle.  A  similar  arrangement 
obtains  in  the  case  of  certain  of  the  muscles  of  the  head,  such 

1  These  figures  and  the  legends  accompanying  them  should  be 
very  carefully  studied.  The  student  should  understand  that  the 
figures  and  diagrams  constitute  a  highly  important  part  of  the  text, 
which  cannot  be  mastered  without  their  use. 


38 

spheres  constitute  by  far  the  larger  part  of  the  human 
brain.  Although  the  neurones  which  compose  them  belong 
to  our  third  adjuster  group,  it  is  common  to  distinguish 
on  the  surfaces  of  the  hemispheres,  known  as  the  cortex, 
(1)  sensory,  (2)  motor,  and  (3)  association  regions.  This 
means  that  nervous  pathways  from  the  sensory  receptors 
come  to  the  surface  in  certain  definite  zones,  that  effector 
tracts  leading  to  muscles  originate  similarly  in  other  zones, 
and  that  the  remainder  of  the  cortical  structure  is  com- 
posed of  nerves  which  join  the  several  regions  with  one 
another.1  Except  that  all  the  senses  are  represented  in  the 
cerebral  cortex,  as  they  are  not  in  the  cord,  this  general 
distribution  is  similar  to,  although  very  much  more  com- 
plex than,  that  of  the  cord.  To  be  sure,  in  the  cord,  the 
'white'  fibrous  matter  is  all  on  the  outer  surfaces,  and  the 
'gray'  cellular  matter  is  wholly  surrounded  by  this  fibrous 

as  the  ocular  muscles,  for  example,  where,  however,  the  imme- 
diately controlling  neurones  issue  not  from  the  spinal  cord,  but 
from  the  brain  stem.  With  this  explanation  and  the  legend 
which  follows,  the  diagram  will  be  easily  understood. 
I,  the  visual  tract;  Ro.  and  Co.,  rods  and  cones;  BC,  bipolar  retinal 
cell;  KG,  large  retinal  ganglion;  TC,  cell-body  in  the  thalamic 
region;  VC,  cell  in  the  visual  cortex  of  the  occipital  region. 
2,  the  auditory  tract;  HC,  hair  cell  of  the  cochlea;  CC,  ganglion 
cell  of  the  cochlea;  MC,  cell  in  the  medulla  oblongata;  TC,  as 
in  the  visual  tract;  AC,  cell  in  the  auditory  cortex  of  the  upper 
temporal  region.  3,  a  cutaneous  tract;  ES,  end-organ  in  the 
skin;  8O,  cell  of  the  spinal  ganglion  on  the  posterior  root  of 
the  cord;  MC  and  TC  as  before;  CS,  sensory  cell  in  the  cortex 
posterior  to  the  Rolandic  region.  4,  an  olfactory  tract,  different 
in  character  from  other  sensory  paths;  OC,  olfactory  sensory 
cell  in  upper  part  of  nasal  cavity;  BC,  cell  in  the  olfactory 
bulb;  COI,  cell  in  the  olfactory  cortex  of  the  hippocampal 
region.  5,  a  motor  tract;  RAW,  motor  cell  of  the  Kolandic 
region ;  8C,  motor  cell  of  the  spinal  cord,  sending  down  a  proc- 
ess to  M,  a  muscle. 

1  Figure  15  exhibits?  certain  interesting  facts  regarding  the  num- 
ber and  location  of  the  neurones  in  the  important  sensory  and 
motor  paths. 


THE  NERVOUS  SYSTEM 


39 


cover,  whereas  in  the  cortex  the  conditions  are  exactly  re- 
versed.    (See  Fig.  16.)     But  the  great  outstanding  differ- 


Fio.  16. — Diagrammatic  section  of  the  cerebral  cortex  taken  at  right 
angles  to  the  surface.  The  right  side  of  the  drawing  illustrates 
the  fiber  system  alone.  The  left  side  illustrates  primarily  the 


40      AN  INTRODUCTION  TO  PSYCHOLOGY 

ence  is  found  in  the  fact  that  mental  processes  are  con- 
nected with  the  action  of  the  cortex  in  a  way  which  seems 
not  to  be  true  of  the  cord. 

Our  knowledge  of  the  facts  which  are  now  to  be  briefly 
stated  rests  in  part  upon  the  teachings  of  anatomy,  which 
has  by  dissection  worked  out  the  topographical  connections 
of  the  different  portions  of  the  brain,  in  part  upon  evidence 
gained  by  experimental  physiology  as  a  result  of  observa- 
tions upon  animals,  and  finally  in  part  upon  the  findings 
of  pathology,  with  its  discoveries  of  the  effect  upon  human 
mental  life  of  injury  to  particular  regions  of  the  brain. 
While  not  in  every  detail  harmonious  and  consistent,  the 
general  indications  of  the  evidence  gained  from  these 
various  sources  are  remarkably  uniform. 

Consciousness  and  the  Cerebral  Cortex. — Conscious 
memory  is  apparently  dependent  upon  the  integrity  of  the 
cerebral  cortex.  If  the  retinae  are  destroyed  by  accident 
or  disease,  blindness  is  the  inevitable  result.  But  memory 
of  visual  objects  need  not  be  impaired.  If,  however,  ex- 
tensive injury  occurs  in  that  part  of  the  cortex  in  which 
the  visual  pathways  terminate,  visual  memory  is  obliterated 
or  gravely  invaded.  Injury  to  other  of  the  so-called  sen- 
sory regions  exercises  a  corresponding  effect  upon  the 
sensory  memories  appropriate  to  the  region  affected.  On 
the  other  hand,  if  the  tissues  of  the  so-called  motor  zone 
are  destroyed,  control  over  particular  muscles  is  lost, 
temporarily,  if  not  permanently.  Injuries  to  the  asso- 
ciation regions  have  more  ambiguous  and  irregular 

cellular  layers.  The  structure  is  so  complex  that  it  is  difficult 
to  display  both  sets  of  facts  in  a  single  sketch.  1,  molecular 
layer  next  the  surface  of  the  brain ;  2  and  3,  layers  of  pyramidal 
cells;  4,  layer  of  polymorphous  cells;  8.F.,  fiber  of  a  sensory 
neurone  entering  to  terminate  in  the  outer  molecular  layer. 
(Modified  from  Morat.) 


THE  NERVOUS  SYSTEM  41 

consequences.  Interesting  experiments  upon  monkeys 
suggest  quite  definitely  that  with  these  animals,  whose 
brain  organization  closely  resembles  our  own,  injuries 
in  the  frontal  association  zone  tend  to  destroy  acquired 
habits,  which  must  then  be  re-learned.  Many  observa- 
tions on  human  beings  had  led  to  the  frequent  con- 
clusion that  these  frontal  regions  were  actively  involved 
in  the  use  of  attention.  The  significance  of  tKe  other  asso- 
ciation zones  is  at  present  somewhat  less  clear,  but  brain 
diseases  indicate  quite  definitely  that  coherent  connection 
of  ideas  is  materially  impaired  by  derangement  at  these 
points.  For  instance,  a  patient  suffering  from  a  disorder 
of  this  type  in  the  parietal  association  region  (see  Fig.  13) 
might  find  it  quite  impossible  to  recognize  the  meaning  of 
a  knife  or  fork,  or  to  remember  the  uses  to  which  they  are 
ordinarily  put,  although  in  such  a  case  there  would  be 
no  question  of  failure  to  see  the  object.  In  the  disease 
called  dementia,  the  tissues  of  the  brain  disintegrate  and 
with  the  disintegration  disappears  all  mental  organization. 
The  attempt  has  sometimes  been  made  to  establish  a  cor- 
respondence between  the  three  great  divisions  of  the  neu- 
rones which  we  have  described,  and  the  fundamental  forms 
of  mental  action.  The  receptors  are  thus  said  to  correspond 
to  sensation.  The  effectors  are  alleged  to  correspond 
to  the  will,  and  the  central  adjusters  are  set  over  against 
memory,  imagination,  and  the  reasoning  processes.  In  so 
far  as  this  formulation  serves  roughly  to  emphasize  cer- 
tain physiological  activities  essential  to  each  of  these  great 
modes  of  mental  expression,  it  is  unobjectionable.  But  if 
understood  in  any  literal  and  precise  fashion,  it  may  be 
seriously  misleading.  Although  the  receptors  are  indis- 
pensable for  sensation,  the  cerebral  cortex  is  also  indis. 


42      AN  INTRODUCTION  TO  PSYCHOLOGY 

pensable;  and  similarly,  while  the  effector  nerves  are 
requisite  to  secure  actual  expression  for  acts  of  will,  the 
motor  cortex  is  quite  as  necessary,  These  considerations 
suggest  the  real  truth  about  the  connection  of  mental  with 
physiological  processes,  i.e.,  that  while  certain  elements  in 
mental  life  depend  in  a  measure  upon  specific  nervous 
structures,  the  entire  nervous  system  is  really  involved  in 
all  mental  occurrences.  A  few  illustrations  will  perhaps 
serve  to  make  the  matter  clear. 

If  with  closed  eyes  one  recalls  the  appearance  of  some 
familiar  object,  we  have  every  reason  to  believe  that  the 
visual  regions  of  the  cerebral  cortex  are  active  and  that 
they  are  more  indispensable  for  this  particular  kind  of 
mental  action  than  any  other  part  of  the  system.  But  we 
have  also  many  reasons  for  believing  that  the  very  process 
by  which  we  attend  to  these  visual  pictures  of  the  object 
recalled,  involves  the  action  of  the  association  areas.  More- 
over, the  securing  and  maintaining  of  a  bodily  attitude 
favorable  to  our  carrying  out  this  undertaking,  e.g.,  closing 
the  eyes,  while  holding  the  large  muscles  of  the  body  firm 
and  quiet,  involves  the  cooperation  of  the  motor  regions  of 
the  cortex  and  the  innervation  of  many  of  the  muscles. 
Again,  to  give  our  attention  to  a  faint  sound  whose  direc- 
tion and  distance  we  are  attempting  to  determine  involves 
primarily  the  auditory  regions  of  the  cortex;  but,  second- 
arily, as  we  put  now  this  interpretation  and  now  that  upon 
what  we  hear,  the  association  regions  of  the  cerebrum 
are  certainly  involved.  Moreover,  it  is  perfectly  obvious 
that  the  movements  of  the  head  which  we  employ  to  assist 
us  in  determining  the  source  of  the  sound,  are  brought 
about  by  impulses  which  in  part,  at  least,  originate  in  the 
motor  cerebral  zones.  The  reader  can,  no  doubt,  supply 


THE  NERVOUS  SYSTEM 


43 


abundant  other  instances  to  support  the  same  general  con- 
clusion, to-wit,  that  the  entire  cortex  is  in  greater  or  lesser 
degree  involved  in  every  mental  act.  The  complex  inter- 
connection of  different  regions  on  the  same  side  of  the 
cortex,  and  of  the  two  sides  of  the  cortex  with  one  another 
and  with  the  lower  brain  centers  is  indicated  in  Figs.  17 
and  18. 


FIG.  17. — Diagram  of  a  vertical  cross  section  from  front  to  back 
through  the  central  region  of  the  cerebral  cortex  to  illustrate 
the  system  of  fibers  connecting  the  cortical  centers  with  one 
another.  (James  after  Starr.) 

This  'integrating'  action  of  the  cortex  by  which  it 
brings  into  a  unified  organized  whole  the  processes  going 
forward  in  various  of  its  parts  extends  also  to  its  super- 
vision over  the  lower  centers.  Impulses  coming  from  the 
spinal  cord  here  combine  with  other  impulses  from  the 
organs  of  special  sense,  like  the  eye  and  the  ear,  and  issue 
in  coordinated  motor  responses.  The  highest  of  these 
forms  of  coordination  occur  when  we  engage  in  a  pro- 


44      AN  INTRODUCTION  TO  PSYCHOLOGY 

longed  and  abstruse  thought  process,  involving  presumably 
large  demands  upon  the  frontal  and  parietal  association 
areas.  Such  a  process  may  then  issue  in  a  decision,  an 


FIG.  18. — Schematic  transverse  section  of  the  human  brain  through 
the  Rolandic  region  to  show  the  crossing  of  motor  fibers  in  the 
neighborhood  of  the  medulla.  In  general  the  right  side  of  the 
brain  controls  the  left  side  of  the  body  and  vice  versa.  S,  fis- 
sure of  Sylvius;  C.C.,  corpus  callosum;  O.  T.,  optic  thalamus; 
C.,  peduncles,  or  legs,  of  the  brain;  P,  the  pons;  M,  medulla 
oblongata ;  VII,  the  facial  nerves  passing  out  from  their  nucleus 
in  the  region  of  the  pons.  (After  James.) 

act  of  will,  given  effect  through  the  muscles  controlling 
speech.  Fig.  19  illustrates  some  simple  coordinations  ex- 
ecuted by  the  brain  in  response  to  sensory  stimulations. 


THE  NERVOUS  SYSTEM 


45 


Possible  Functions  of  the  Optic  Thalami. — Recent 
clinical  studies  have  given  ground  to  believe  that  certain 
regions  at  least  of  the  great  group  of  nervous  elements 
known  as  the  optic  thalami  (see  Figs.  10,  11,  12)  are  per- 


Fio.  19. — Diagram  to  show  the  cortical  pathways  involved  when  one 
speaks  or  writes  in  response  to  what  is  seen  or  heard.  A  is  the 
auditory  center,  V,  the  visual,  W,  the  writing,  and  E,  that  for 
speech.  (After  James.) 

haps  the  centers  upon  which  the  affective  parts  of  our 
mental  experiences  depend,  i.e.,  the  agreeableness  or  dis- 
agreeableness  of  our  sensations  and  ideas.  The  evidence 
can  hardly  be  called  conclusive,  but  it  is  certainly  very 


46  AN  INTRODUCTION  TO  PSYCHOLOGY 

suggestive  and  the  reader  will  have  observed  that  no 
region  of  the  cerebral  cortex  has  been  made  responsible  for 
these  conspicuous  factors  in  mental  life. 

The  Autonomic  System. — While  our  sensations,  our 
memories,  our  reasonings,  and  our  acts  of  will  are,  in  a 
true  and  proper  sense,  dependent  upon  the  central  nerv- 
ous system,  and  particularly  upon  the  cerebral  cortex,  the 
autonomic  system  plays  a  very  important  part  in  our 
mental  experience  and  deserves  some  further  comment. 
This  division  of  the  nervous  system  got  its  name  because 
it  was  supposed  to  be  essentially  self -controlling,  and  self- 
directing. 

The  autonomic  system,  like  the  central  system,  is  com- 
posed of  groups  of  neurones.  These  neurones,  although 
they  differ  somewhat  in  appearance  from  the  nerves  of  the 
central  system,  are  nevertheless  of  essentially  similar  struc- 
ture. The  largest,  and  in  many  ways  the  most  important 
group,  consists  of  the  so-called  sympathetic  system,  which 
is  made  up  of  two  great  strands  of  fibers  and  cell  bodies, 
placed  one  on  either  side  of  the  spinal  cord,  with  which 
they  are  connected  by  very  complicated  arrangements  of 
fibers.  (See  Fig.  8.)  Other  groups  of  these  autonomic 
neurones  are  found  distributed  through  the  viscera  and  at 
various  points  throughout  the  skull  cavity.  For  example, 
one  highly  important  group  is  located  in  the  muscular 
walls  of  the  heart;  another  is  connected  with  the  walls  of 
the  stomach.  Still  others  control  certain  of  the  glands 
and  muscles  of  the  eye. 

It  is  through  the  operations  of  the  sympathetic  system 
that  all  the  great  vital  processes  of  digestion,  respiration, 
and  circulation  are  carried  forward.  The  beating  of  the 
heart  is  brought  about  by  nervous  impulses  which  originate 


THE  NERVOUS  SYSTEM  47 

in  the  autonomic  neurones  in  its  own  muscle  walls,  although 
the  rate  of  the  contractions  is  influenced  by  the  medulla. 
The  contractions  of  the  muscle  fibers  of  the  stomach  and 
intestines,  the  secretion  of  the  various  fluids  required  by 
the  digestive  process,  these  and  all  the  other  features  of 
the  assimilation  of  foodstuffs  and  the  excretion  of  waste 
products  are  carried  out  by  the  neurones  of  this  system.  In- 
asmuch as  these  vital  functions,  including  respiration  and 
the  circulation  of  the  blood,  are  ordinarily  unconscious,  it 
might  seem  as  though  this  part  of  the  nervous  system  were 
unimportant  for  mental  life.  Of  course,  one  can  readily 
understand  that  only  on  the  basis  of  reasonably  healthful 
organic  conditions  may  one  expect  to  live  a  normal  mental 
life,  and  in  so  far  the  dependence  of  our  conscious  processes 
upon  the  autonomic  system  is  self-evident.  But  there  is 
a  much  more  significant  set  of  facts  to  be  taken  into 
account. 

The  most  exciting  parts  of  our  experience  are  undoubt- 
edly found  in  our  emotions.  So  long  as  our  affairs  run 
along  smoothly,  we  hardly  ever  remark  their  mental  char- 
acter. But  the  moment  they  become  in  any  way  exciting, 
whether  they  cause  us  apprehension  and  solicitude,  or  the 
delights  of  thrilling  anticipation,  we  suddenly  become 
cognizant  of  a  group  of  factors  which  under  other  condi- 
tions appear  to  be  wholly  lacking.  In  fear,  and  even  em- 
barrassment, the  heart  misbehaves  itself  in  a  way  to  at- 
tract our  painful  notice.  This  misbehavior  is  occasioned  by 
the  neurones  of  the  autonomic  system,  and  without  antici- 
pating at  this  point  the  more  detailed  analyses  which  we 
shall  have  occasion  to  make  in  a  later  chapter,  we  may 
content  ourselves  with  the  general  statement  that  many  of 
the  characteristic  features  of  emotion  are  to  be  found  in 


48  AN  INTRODUCTION  TO  PSYCHOLOGY 

bodily  reactions  for  which  the  autonomic  system  is  very 
largely  responsible.  Kecent  investigations  have  shown  that 
in  emotions  like  anger  and  fear,  the  secretions  of  certain 
internal  glands,  the  adrenals,  play  a  very  important  part. 
The  activity  of  the  salivary  glands  and  the  tear-producing 
glands  in  certain  emotions  will  suggest  other  instances  of 
the  glandular  accompaniments  of  states  of  excitement. 

The  facts  presented  in  the  last  few  paragraphs  will 
serve  to  give  point  to  the  statement  made  early  in  this 
chapter,  that  the  central  system  and  the  autonomic  system 
are  most  intimately  related  to  one  another,  and  that  both 
are  fundamentally  significant  for  the  activities  of  the  mind. 


CHAPTER  IV 
CONSCIOUSNESS  AND  HABIT  FORMATION 

Relation  of  Consciousness  to  Instinctive  and  Auto- 
matic Acts. — One  fundamental  conception  runs  through 
this  book,  which  may  be  conveniently  introduced  at  once. 
This  is  the  theory  that  conscious  acts  arise  amid  the  heredi- 
tary reflex  and  instinctive  acts,  like  swallowing,  crying, 
sleeping,  and  pass  over  into  non-conscious  habits,  such  as 
writing  and  walking.  We  may  now  explain  more  fully 
just  what  is  meant  by  this  idea. 

The  general  conception  of  consciousness  as  a  part  of 
the  adjusting  equipment  of  the  organism  has  prepared  the 
reader  to  appreciate  the  fact  that  if  the  reflex  and  heredi- 
tary responses  of  the  organism  to  its  environment  were 
wholly  satisfactory  for  the  maintenance  of  the  life  of  the 
individual  and  the  race,  there  would  be  no  particular  justi- 
fication for  the  appearance  of  consciousness,  and  certainly 
no  available  explanation  of  it  on  evolutionary  grounds.  It 
is  a  natural  consequence  of  this  view  to  look  for  the 
appearance  of  conscious  processes  at  those  points  both  in 
individual  and  racial  development  where  reflex  and  heredi- 
tary automatic  acts  are  inadequate  to  meet  environmental 
demands. 

So  far  as  concerns  the  history  of  the  individual,  this 
conception  seems  sound  enough.  In  so  far  as  the  needs 
of  the  organism  are  adequately  met  in  the  early  life  of 
infancy,  consciousness  is  present  in  only  a  fleeting  and 


50  AN  INTRODUCTION  TO  PSYCHOLOGY 

interrupted  way.  But  as  development  takes  place,  the 
organism  is  exposed  to  a  large  variety  of  conditions  in 
which  the  hereditary  equipment  is  hopelessly  inadequate 
to  cope  with  the  situation.  At  such  points  consciousness  is 
always  to  be  found. 

Similarly  in  the  history  of  the  race,  the  points  at 
which  the  evidences  of  mind  are  most  unequivocal  are 
those  in  which  a  purely  mechanical,  stereotyped  response 
of  the  ordinary  hereditary  kind,  is  obviously  ill-adapted 
to  steer  its  possessor  and  his  offspring  through  the  vicissi- 
tudes of  life. 

The  general  doctrine  of  this  chapter,  then,  is  that  once 
neuro-conscious  process  has  contributed  to  the  establish- 
ment of  needed  coordinations,  it  leaves  its  accomplishments 
behind  for  use  by  the  non-conscious  devices  of  the  nervous 
system  and  itself  goes  forward  to  new  tasks. 

Attention  has  been  called  in  a  previous  chapter  to  the 
fact  that  the  human  organism  possesses  a  considerable 
group  of  motor  activities  which  are  supplied  it  by  nature 
and  which  serve  the  more  immediate  purposes  of  support- 
ing life.  These  acts  are  illustrated  in  the  various  reflexes 
which  are  for  the  most  part  unconscious,  and  in  those 
automatic  acts  by  which  digestion,  circulation,  respiration, 
and  the  other  life-sustaining  bodily  functions  are  carried 
on.  Over  against  these  forms  of  action  are  the  acquired 
habits,  such  as  walking,  talking,  writing,  and  the  like. 
All  of  these  when  perfected  exhibit  at  times  a  considerable 
degree  of  freedom  from  conscious  supervision. 

Part  Played,  by  Consciousness  in  Learning  New  Acts. 
—While  one  is  learning  to  write,  consciousness  is  involved 
in  the  most  alert  and  intense  manner.  The  position  of 
the  hand,  the  mode  of  grasping  the  pen,  the  model  to  be 


CONSCIOUSNESS  AND  HABIT  FORMATION        51 

copied,  the  movement  necessary  to  form  each  part  of  the 
letter — all  these  things,  one  after  the  other,  are  the  objects 
of  vivid  attention.  As  mastery  is  gradually  gained  of  now 
one  and  now  another  step  in  the  process,  conscious  super- 
vision becomes  more  and  more  indirect  and  incidental,  until 
finally,  with  the  acquirement  of  complete  control  over  the 
coordination,  one  is  able  to  give  almost  exclusive  attention 
to  the  thoughts  which  are  to  be  put  upon  paper,  retaining 
only  the  most  general  oversight  of  the  writing  act  itself. 

An  acquirement  of  this  kind  is  spoken  of  as  a  habit,  and 
once  such  a  habit  is  thoroughly  mastered,  it  can  be  taken 
up  into  the  formation  of  a  larger  habit  in  which  it  then 
becomes  a  member.  Thus  a  bank  clerk  is  likely  to  estab- 
lish a  fairly  fixed  routine  for  his  daily  work,  which  soon 
becomes  habitual;  but  in  this  larger  habit  are  included 
such  less  automatized  acts  as  writing,  adding,  subtracting, 
multiplying  and  dividing. 

This  illustration  may  serve  in  a  homely  way  to  exhibit 
what  is  meant  by  the  doctrine  formulated  above.  Mental 
process  seems  always  to  find  its  appropriate  place  in  con- 
nection with  the  upbuilding  of  just  such  habits.  When 
these  have  become  sufficiently  perfect,  they  are  passed  over 
almost  entirely  to  the  automatic  control  of  the  nervous  sys- 
tem, leaving  the  mind  itself  free  to  go  forward  to  the 
creation  of  other  habits,  or  to  the  construction  of  groups 
of  habits  in  which  these  smaller  components  may  find  a 
place.  Our  social  and  physical  surroundings  generally 
change  enough  to  prevent  us  from  reducing  our  actions 
wholly  to  the  habitual  type.  We  are  constantly  challenged 
to  make  new  adjustments.  The  mind  itself,  then,  is  always 
moving  on  to  new  conquests,  is  always  literally  seeking 
new  worlds  to  conquer.  This  at  least  is  true  in  a  bona 


52     AN  INTRODUCTION  TO  PSYCHOLOGY 

fide  way  as  long  as  we  continue  to  grow  mentally.  In  the 
natural  course  of  any  human  life,  there  conies  a  period  when 
we  literally  cease  to  grow,  followed  by  a  period  when  our 
mentality  begins  to  decay.  All  statements  about  mental 
growth  must  therefore  be  made  subject  to  the  qualifica- 
tions implied  in  this  situation. 

There  are  certain  interesting  aspects  of  this  process  of 
acquiring  automatic  habits  or  coordinations  which  it  will 
be  profitable  to  pass  in  brief  review. 

Origin  and  Utility  of  Spontaneous  Movements. — In 
the  first  place,  then,  it  should  be  understood  that  in  addi- 
tion to  the  strictly  reflex  acts,  there  are  innumerable 
movements  of  the  muscles  of  the  limbs  and  body  made  by 
little  babies  long  before  they  are  really  able  to  control 
their  actions.  During  their  waking  moments  the  muscles 
of  the  face,  hands,  and  feet  of  the  youngest  children  are 
often  in  active  motion.  These  spontaneous  or  random 
movements,  as  they  are  sometimes  called,  constitute  the 
material  of  which  the  later  controlled  movements  are 
largely  composed.  In  some  fashion  or  other,  with  the 
details  of  which  we  are  frankly  but  imperfectly  acquainted, 
intelligence  steps  in  and  organizes  these  miscellaneous  and 
somewhat  accidental  movements  into  effective  coordinated 
acts.  Certain  general  features  of  the  process  we  can  de- 
scribe, partly  on  the  basis  of  our  observation  of  children 
during  the  process  of  their  growth  in  muscular  control, 
and  partly  by  analysis  of  our  own  adult  performances 
when  learning  a  new  act  of  skill. 

One  of  the  first  expressions  of  voluntary  control  in  a 
baby  is  found  in  the  process  by  which  it  learns  to  extend 
its  hand  and  grasp  objects  which  are  seen.  There  seems 
to  be  a  general  disposition  for  all  strong  sensory  stimula- 


CONSCIOUSNESS  AND  HABIT  FORMATION        53 

tions  to  drain  off  into  widespread  bodily  movements.  This 
fact  seems  natural  enough  in  view  of  the  tendency  of 
sensory  nerves  to  carry  impulses  forward  into  muscles. 
The  stronger  the  impulse,  the  more  widely  we  may  reason- 
ably expect  to  find  its  results  distributed  in  the  muscle 
groups.  Whether  all  the  movements  of  hands  and  arms 
which  one  may  observe  in  a  young  child  are  occasioned  by 
immediately  present  sense  stimulations,  or  whether  some 
of  them  may  proceed  from  a  sort  of  internal  nervous  ex- 
plosion, we  do  not  know.  At  all  events  it  is  intelligible 
that  bright  and  shining  objects,  such  as  are  first  to  catch 
and  hold  a  baby's  visual  attention,  should  elicit  among 
other  responses  vigorous  movements  of  the  arms  and  hands. 
As  a  consequence,  it  is  almost  certain  sooner  or  later  to 
occur  that  some  of  these  movements  will  result  in  bringing 
the  object  seen  into  contact  with  the  hand.  Indeed,  par- 
ents are  sure  to  expedite  and  facilitate  this  outcome  by 
putting  objects  where  they  can  be  readily  seized.  It  so 
happens  that  in  early  infancy  there  is  an  essentially  reflex 
tendency  to  close  the  hand  upon  objects  which  stimulate 
the  skin  of  the  fingers  and  palms.  So  strong  is  this  reflex 
that  newly  born  infants  can  sustain  their  own  weight  by 
grasping  a  small  rod. 

Establishment  of  Successful  Coordinations.— There  is 
a  good  deal  of  diversity  of  opinion  among  psychologists 
as  to  the  processes  which  intervene  between  this  initial 
experience  of  grasping  an  object  seen,  and  the  final 
achievement  of  the  skilful  control  possessed  by  adults. 
There  can  be  no  question  that  in  the  early  stages  of  the 
development  of  such  a  habit  there  is  often  a  condition  of 
great  excitement  and  keen  pleasure.  Such  conditions 
seem  favorable  to  the  rapid  stamping  in  upon  the  nervous 


54  AN  INTRODUCTION  TO  PSYCHOLOGY 

system  of  those  impressions  which  will  conduce  most 
quickly  to  the  securing  of  an  automatic  habit.  Certain  it 
is  that  either  lack  of  interest,  or  the  presence  of  painful 
sensations  at  any  stage  of  the  process,  tends  to  discourage 
and  disintegrate  the  growing  coordination. 

It  must  not  be  supposed  that  success  in  one  attempt 
necessarily  implies  equal  success  in  all  succeeding  attempts. 
In  general,  the  progress  from  the  initial  stage  to  the  per- 
fected habit  is  slow  and  irregular,  and  in  the  case  of  the 
great  majority  of  the  motor  accomplishments  of  little 
children  is  brought  about  by  a  process  known  to  psycholo- 
gists as  trial  and  error,  and  in  ordinary  parlance,  as  'try, 
try  again.'  In  certain  forms  of  adult  learning,  of  which 
we  shall  have  something  to  say  at  a  later  point,  there  is 
an  obvious  attempt  to  make  use  of  reflection  and  reason- 
ing, to  see  how  and  why  a  particular  movement  ought  to 
be  made  and  then  to  go  about  the  making  of  it.  But  in 
these  primitive  forms  of  acquiring  control,  the  first 
method  is  chiefly  in  evidence. 

In  one  and  all  these  cases,  the  point  to  be  carefully 
borne  in  mind  is  that  during  the  learning  stage  there  is 
a  very  vivid  consciousness  of  what  is  going  on  step  by 
step ;  whereas  after  the  act  is  substantially  mastered  there 
may  be  only  the  most  indirect  and  casual  conscious  super- 
vision. 

Elimination  of  Useless  Movements. — One  striking  fea- 
ture distinguishing  the  earlier  from  the  later  stages  in 
these  learning  processes  is  found  in  the  presence  at  the 
outset  of  large  numbers  of  superfluous  movements,  some 
of  which  are  merely  useless,  while  others  actually  hinder 
progress.  In  the  perfected  habit,  almost  all  of  these  have 
been  eliminated.  It  is  as  though  Nature  called  out  from 


CONSCIOUSNESS  AND  HABIT  FORMATION        55 

the  organism  a  surplus  of  movements,  among  which  may 
haply  be  found  the  little  group  indispensable  for  the 
specific  purpose  in  hand.  The  process  of  establishing  the 
coordination  consists,  then,  first  in  the  selection  and  fixa- 
tion of  the  essential  motor  elements  from  among  move- 
ments actually  occurring,  and  second,  in  the  gradual 
elimination  of  those  which  are  needless.  Abundant  con- 
firmation of  these  statements  may  be  found  in  observing 
a  child  while  he  is  acquiring  control  over  almost  any  motor 
dexterity.  Writing,  as  we  have  already  suggested,  is  apt  at 
the  outset  to  involve  a  great  mass  of  perfectly  needless 
movements  of  head,  tongue,  shoulders,  and  body.  Slowly 
these  fall  away,  until  there  are  left  substantially  only 
such  motions  as  are  really  required.  Gracefulness  has 
sometimes  been  declared  to  depend  upon  the  use  of  only 
essential  movements.  However  true  this  definition,  it  cer- 
tainly may  be  adopted  as  a  just  description  of  economic 
efficiency.  It  underlies  all  the  attempts  to  secure  maximal 
efficiency  in  industrial  occupations. 

Habit  and  the  Sensory-Motor  Circuit. — The  mechanism 
of  many  of  these  habitual  coordinations  which  stop  just 
short  of  becoming  entirely  automatic  and  non-conscious, 
seems  to  depend  upon  the  linking  together  of  sensations 
and  movements  in  a  manner  which  may  well  be  briefly 
described.  In  learning  to  ride  a  bicycle,  for  example,  con- 
siderable groups  of  muscular  movements  are  necessarily 
combined.  Everyone  who  has  gone  through  the  experi- 
ence will  probably  recall  that  one  of  the  early  difficulties 
consisted  in  remembering  to  push  downward  with  one 
foot  at  just  the  appropriate  moment,  as  reported  by  sen- 
sations from  various  parts  of  the  body,  particularly  from 
the  knees  and  ankles  and  soles  of  the  feet.  One  quickly 


56      AN  INTRODUCTION  TO  PSYCHOLOGY 

learned,  however,  to  respond  to  these  signals  and  to  make 
the  corresponding  downward  thrust  with  the  proper  foot. 
As  soon  as  this  interconnection  of  sensations  and  move- 
ments is  firmly  established,  the  process  of  pedalling  largely 
takes  care  of  itself,  and  the  entire  attention  may  be  given 
to  learning  to  balance.  Until  this  point  is  reached,  many 
beginners  find  themselves  with  feet  in  the  air  or  'back- 
pedalling' to  the  entire  defeat  of  their  forward  progress. 
The  accompanying  diagram  (Fig.  20)  may  serve  rudely 


si 


M 


FIG.  20. — Diagram  to  illustrate  a  series  of  motor  discharges  in  re- 
sponse to  sensory  or  ideational  stimulations.  81,  a  sensory  or 
ideational  stimulus;  M,  a  motor  response;  S,,  a  sensory  dis- 
turbance occasioned  by  the  movement  M;  M2,  a  motor  discharge 
consequent  upon  the  stimulation  Slt  etc.  In  an  act  like  skating 
two  general  sets  of  alternating  movements  may  be  repeated 
again  and  again.  In  such  an  act  as  signing  one's  name  each  of 
the  movements  may  be  different  from  the  others. 

to  illustrate  this  situation.  When  a  movement  is  made, 
we  become  aware  of  it  partly  through  the  sensations  which 
are  aroused  in  the  muscles  and  joints  of  the  member  moved, 
and  partly  by  means  of  sensory  effects  impressed  upon 
other  sense  organs.  Either  type  of  sensation  may  be  used 
to  serve  as  the  signal  for  the  next  movement.  In  playing 
a  musical  instrument  there  are  thus  aroused  not  only  sen- 
sations in  the  skin  of  the  hand  and  in  the  muscles  of  the 
hand  and  arm,  but  also  sensations  of  sound;  and  if  the 
eyes  are  properly  directed,  there  may  be  a  visual  report  of 


CONSCIOUSNESS  AND  HABIT  FORMATION        57 

the  movement.  Any  or  all  of  these  sensations  may  serve 
as  signals  for  the  series  of  movements.  Where  habits  have 
become  highly  automatized,  it  seems  probable  that  this  same 
type  of  sensory-motor  mechanism  is  employed,  but  that  in 
some  manner  it  short-circuits  the  higher  cerebral  regions, 
so  that  we  are  much  less  definitely  conscious  of  the 
process. 


CHAPTER    V 
ATTENTION 

The  previous  chapters  have  brought  to  the  reader's  notice 
the  conception  of  life  as  adjustment,  and  have  explained  the 
dependence  of  the  mental  parts  of  the  adjusting  process 
upon  the  organization  of  the  nervous  system.  We  must 
now  turn  to  a  more  intensive  and  detailed  analysis  of  this 
process. 

Attention  as  Adjustment. — When  an  animal  organism  is 
subjected  to  a  strong  physical  stimulus,  for  example,  an 
acid,  it  instantly  displays  protective  movements,  generally 
of  retreat.  Such  movements  are  obviously  of  an  adaptive 
character.  Man,  under  similar  conditions  of  stimulation, 
by  strong  lights,  extreme  temperatures,  loud  sounds,  and 
the  like,  also  manifests  adjustive  responses.  In  this  case, 
however,  as  we  all  know  from  personal  experience,  these 
adaptive  reactions  are  accompanied  by  the  mental  state 
which  we  call  attention.  Attention  is,  indeed,  the  most 
general  attitude  of  adjustment,  and  we  may  profitably  di- 
rect our  thought  to  certain  of  its  more  important  char- 
acteristics. 

We  seem  to  be  so  organized  that,  regardless  of  our  mo- 
mentary occupation,  any  sense  stimulus  of  sufficient  vio- 
lence may  force  its  way  over  the  receptors  and  into  the 
cerebral  cortex,  where  it  may  displace  the  dominant  nerv- 
ous activities  and  itself  take  possession.  Such  a  nervous 
assault  upon  the  brain  results  in  our  becoming  aware  of  the 
object  acting  as  stimulus,  produces  what  we  call  attention 

58 


ATTENTION  59 

to  it.  Now  it  is  an  interesting  fact  that,  as  part  of  the 
process  of  attending,  the  action  of  the  nervous  system 
evokes  certain  muscular  adjustments,  as  a  consequence  of 
which  we  become  more  definitely  and  distinctly  aware  of  the 
stimulus.  To  illustrate,  if  a  strong  light  strike  the  eyes 
from  the  side,  there  is  a  rotation  of  the  eyeballs  and  often 
a  turning  of  the  head,  as  a  result  of  which  the  eyes  are 
put  in  the  position  of  clearest  and  most  distinct  vision. 
At  the  beginning  of  the  process,  we  may  have  been  aware 
only  of  the  vague  but  strong  impression  of  light  and  color. 
As  the  eyes  turn  and  we  are  able  to  see  distinctly,  we  secure 
an  impression  of  the  luminous  object  which  is  both  vivid  and 
clear.  Such  an  impression  affords  us,  as  the  original  pow- 
erful but  indistinct  impression  did  not,  information  as  to 
the  character  of  the  object,  and  we  are  forthwith  in  a  posi- 
tion to  determine  intelligently  our  next  movement. 

Any  strong  stimulus  constitutes  a  more  or  less  imperious 
invitation  to  an  adjustive  response.  Figuratively,  at  least, 
and  often  literally,  such  a  stimulus  is  in  the  nature  of  a 
problem  which  we  are  called  upon  to  solve.  Certainly  it 
presents  in  a  fair  sense  a  difficulty  which  we  must  sur- 
mount. The  first  step  in  the  process  of  mental  adjustment 
is  always  attention,  and  as  our  previous  discussion  has 
suggested,  this  adjustment  will  normally  be  found  to  in- 
volve motor  reactions  designed  to  put  us  in  a  position  of 
more  distinct  and  complete  perception  of  the  situation. 

Attention  as  an  Organizing  Activity. — Our  ordinary 
language  tends  to  create  a  somewhat  misleading  impression 
concerning  attention,  because  it  suggests  that  attention  is 
a  separate  force  or  entity  which  may  suddenly  step  in  and 
direct  our  mental  processes.  Thus  we  say  that  attention 
wandered,  or  that  it  was  concentrated,  and  properly  under- 


60 


AN  INTRODUCTION  TO  PSYCHOLOGY 


stood  such  phrases  are  perfectly  correct.  Evidently  these 
expressions  imply  that  attention  is  simply  preparatory 
mental  and  motor  adjustment.  It  is  an  act,  not  an  agent. 
It  is  the  process  in  which  is  mentally  organized  whatever  is 
at  the  moment  presented.  This  fact  is  made  clear  by  observ- 
ing that  we  may  attend  to  one  and  the  same  physical  object 
in  a  number  of  different  ways,  depending  upon  the  manner 


FIG.  21. 

in  which  mentally  we  organize  its  constituents.  For  ex- 
ample, Fig.  21  may  be  attended  to  as  a  picture  frame,  or 
as  a  truncated  pyramid,  with  the  apex  toward  the  observer, 
or  as  a  square  tunnel  into  which  one  is  looking.  So  far  as 
the  physical  object  is  concerned,  the  lines  are  in  each  case 
one  and  the  same.  So  far  as  concerns  the  stimulation  of 
the  retina  the  situation  may  be  wholly  unchanged  in  the 
three  instances.  But  our  mode  of  attending  is  in  each  case 
quite  distinct,  because  we  organize  and  interpret  the  lines 
from  three  different  mental  points  of  view. 

The  Field  of  Attention. — Psychologists  have  been  par- 
ticularly interested  in  one  aspect  of  attention  about  which  a 
few  words  must  be  said.  When  one  is  reading,  at  any  given 


ATTENTION  61 

moment  a  certain  word  or  group  of  words  stands  out  with 
greater  clearness  than  the  rest  of  the  words  on  the  page, 
while  outside  the  page  altogether,  one  may  be  dimly  con- 
scious of  objects  in  the  outer  part  of  the  field  of  view.  More- 
over, as  one  reads,  ideas  more  or  less  disconnected  with  the 
words  to  which  one  is  dominantly  attentive  may  from  time 
to  time  intrude  themselves.  This  situation  has  been  de- 
scribedjby_saying  that  the  fiejj^ofjltention  has  a  focus  and 
a  margin.  The  focus  is  comprised  of  whatever  may  be  at 
the  moment  clearest  and  most  distinct  in  consciousness. 
Outside  this  focal  region  there  is  a  margin  of  indefinite 
extent,  made  up  of  materials  which  are  decreasingly  clear 
as  one  passes  away  from  the  focus.  Observers  differ  as  to 
the  number  of  discernible  zones  of  clearness.  Some  persons 
report  only  two  regions,  one  the  central  region  of  maximal 
clearness,  the  other  the  entire  remaining  portion  of  the 
field.  Others  maintain  that  three  or  four  or  even  more  dis- 
tinct areas  may  be  distinguished,  differing  in  clearness  all 
the  way  from  the  central  focus  through  progressively  dim- 
mer and  less  distinct  regions  to  a  margin  which  is  essentially 
unconscious.  Fig.  22  will  suggest  the  sort  of  thing  here 
described. 

The  Range  of  Attention. — The  conception  of  attention 
as  a  process  of  adjustment  would  lead  us  naturally  to  ex- 
pect that  we  should  at  any  one  instant  be  able  to  attend  only 
to  a  small  group  of  objects  or  ideas.  It  has  often  been  urged 
that  we  can  attend  to  only  one  thing  at  a  time,  and  there 
is  perhaps  a  sense  in  which  this  is  true,  but  it  involves 
recognizing  the  fact  that  this  'thing'  may  be  quite  complex, 
and  may  involve  what  under  ordinary  conditions  we  should 
regard  as  a  number  of  objects.  A  few  illustrations  will  per- 
haps make  the  matter  clear. 


62  AN  INTRODUCTION  TO  PSYCHOLOGY 

A  person  playing  the  piano  from  a  printed  score  may 
seem  to  be  attending  to  a  great  many  different  things  at 
once.  The  eyes  take  in  several  groups  of  notes  and  then 
perhaps  are  quickly  turned  to  glance  at  the  hands  and 
keyboard.  In  looking  at  the  music,  a  considerable  number 
of  separate  notes  may  be  taken  in  at  a  glance,  each  of 
which  indicates  a  particular  movement  of  a  particular  fin- 


2 

~J 
"4 


FIG.  22. — 1,  the  focal  region  of  attention;   2  and  3,  zones  of  less 
distinct  awareness;  4,  the  region  of  subconscious  processes. 

ger,  together  with  the  time  value  and  the  stress  with  which 
the  key  is  to  be  pressed  down.  Such  a  situation  appears 
to  involve  attending  simultaneously  to  a  large  group  of 
objects,  but  it  would  involve  a  misapprehension  of  the  actual 
situation  to  suppose  that  in  any  one  moment  they  were  per- 
ceived as  so  many  separate  and  distinct  things.  By  long 
training  the  eye  has  been  taught  to  take  in  groups  of  notes 
in  a  single  sweep,  exactly  as  it  takes  in  the  groups  of  letters 
which  compose  a  short  word.  The  response  of  the  fingers 
to  what  the  eye  sees  is  in  the  same  way  the  result  of  long 
and  painstaking  practice,  and  the  proficient  performer  does 
not  require  to  give  separate  attention  to  each  movement. 
Obviously  there  is  a  very  real  difference  between  attend- 


ATTENTION  63 

ing  at  any  one  moment  to  a  large  number  of  objects  and 
doing  at  one  and  the  same  instant  a  considerable  number 
of  different  things.  The  limit  of  our  ability  to  perform 
complicated  simultaneous  movements  as  a  result  of  practice 
would  be  hard  to  set.  Certainly  the  least  skilful  of  us  can 
master  a  good  many  such  movements.  But  however  complex 
the  object  to  which  we  attend,  apparently  the  process  of  at- 
tention serves  to  bring  together  into  a  sort  of  mental  unit 
all  the  different  parts.  How  many  such  parts  can  actually 
be  united  is  only  to  be  determined  by  experiment.  Four  or 
five  dots  placed  close  together  on  a  piece  of  paper  can  be 
seen  in  a  single  glance.  If  they  be  gradually  spread  some- 
what further  apart,  it  will  soon  be  difficult  or  impossible 
to  see  them  without  breaking  them  up  into  successive 
groups.  Similarly,  six  or  seven,  or  even  eight  very  rapidly 
succeeding  sounds  may  be  heard  as  a  unit.  If  the  sounds 
be  given  more  slowly,  they  will  begin  to  break  up  into 
smaller  groups. 

There  is  no  serious  difficulty  in  determining  by  experi- 
ments what  are  the  facts  about  this  so-called  range  or 
scope  of  attention  when  we  are  dealing  with  physical 
objects.  It  is  much  more  difficult  to  speak  with  certainty 
about  our  ability  to  attend  to  groups  of  ideas.  When  one 's 
mind  is  engaged  upon  the  solution  of  a  problem,  ideas  may 
flow  through  it  with  amazing  rapidity,  and  we  often  speak 
as  though  while  thinking  about  certain  parts  of  a  problem, 
we  kept  the  rest  of  it  constantly  before  us.  Suffice  it  to 
say  that  most  psychologists  are  agreed  that  the  situation 
is  substantially  identical  with  that  already  examined  in 
the  case  of  attention  to  objects.  However  complex  an  idea 
may  be,  attention  at  any  given  instant  is  probably  always 
occupied  with  one  such  idea  and  its  immediate  relations. 


64      AN  INTRODUCTION  TO  PSYCHOLOGY 

The  Duration  of  Attention. — This  discussion  leads  very 
naturally  to  another  issue  which  has  always  interested 
psychologists,  i.e.,  how  long  can  we  attend  to  any  one 
thought  or  thing  ?  Common  opinion  would  lead  one  to  sup- 
pose that  we  may  attend  almost  indefinitely.  Certainly 
we  speak  of  having  had  this,  that  or  the  other  thought  in 
mind  for  a  long  time.  In  the  same  way  we  say,  "I  have 
been  watching  that  bird  for  ten  or  fifteen  minutes,"  im- 
plying that  our  attention  has  been  unchanged  through  all 
that  period.  In  a  practical  sense,  no  doubt  both  types  of 
statement  are  sufficiently  accurate.  But  a  very  brief 
scrutiny  of  the  actual  facts  in  such  cases  will  give  us  quite 
a  different  impression  of  what  it  is  that  occurs. 

Careful  observation  will  show  that  what  we  might  justly 
enough  speak  of  as  'attending  to  a  bird'  involves  in  reality 
attending  to  an  ever  changing  series  of  facts  about 
the  bird.  We  note  now  the  color  of  his  wings,  now  the 
shape  of  his  tail,  now  the  movement  of  his  head,  and  now 
his  change  of  position  from  one  branch  to  another.  If  we 
attempt  to  focus  our  attention  rigidly  upon  any  single 
feature,  such  as  the  shape  of  his  beak,  suddenly  and  with- 
out intending  it,  we  are  noting  some  other  feature;  or,  to 
our  surprise,  we  may  find  that  some  totally  disconnected 
thought  has  bobbed  up  in  our  minds  and  taken  off  our 
attention.  In  the  same  way,  if  we  examine  what  occurs 
when  our  thought  is  supposedly  riveted  upon  some  par- 
ticular idea,  we  shall  discover  that  in  actual  fact  a  great 
series  of  ideas  has  passed  through  our  minds,  each  of  which 
was  perhaps  related  to  the  thought  with  which  we  were 
ostensibly  occupied,  but  each  of  which  is  quite  certainly 
a  separate  thought.  In  othe,r  words,  our  attention  moves 
very  rapidly  and  never  in  any  literal  sense  lingers  long 


ATTENTION  65 

in  one  place.  How  long  it  remains  it  is  very  difficult  to 
say.  Experiments  would  indicate  that  a  few  seconds  is 
ordinarily  the  outside  limit. 

Attention  and  Organized  Reaction. — If  we  now  turn 
back  and  recall  the  assertion  that  attention  is  essentially 
a  process  of  adjustment,  we  shall  see  very  good  reason 
why  the  attentive  act  should  tend  to  bring  together  into 
a  single  mental  object  as  many  as  possible  of  the  separate 
elements  to  which  adjustment  must  be  made.  We  can 
also  discern  a  reason  why  attention  should  be  relatively 
brief  in  its  duration. 

In  primitive  animal  conditions,  adjustment  implies  an 
immediate  response  to  a  present  situation,  and  generally 
a  situation  in  which  some  localized  stimulus  demands  a 
localized  response.  Even  in  the  life  of  man,  the  ordinary 
sensory  stimulus  demanding  an  adjustive  activity  re- 
quires a  localized  reaction.  A  blow  upon  the  hand  de- 
mands an  adjustment  which  will  promptly  remove  the 
hand  from  danger.  The  sight  of  food  similarly  requires 
a  localized  type  of  response  designed  to  secure  it.  In  the 
higher  animals,  and  particularly  in  man,  many  of  these 
adjustments  find  their  crucial  significance  in  future  re- 
actions, in  delayed  responses.  You  make  a  decision  today 
which  you  cannot  execute  until  tomorrow.  In  each  and 
every  case  the  reaction,  whether  immediate  or  delayed, 
must  be  organized  to  be  effective,  and  it  must  have  rela- 
tion to  a  situation  which  is  a  unit  in  the  sense  that  it 
requires  a  particular  kind  of  response.  To  attend  to  put- 
ting air  in  your  automobile  tires  involves  attending  not 
to  the  tires  in  general,  but  to  each  one  separately,  and  to 
a  series  of  particular  acts  in  each  case — unscrewing  the 
valve  cap,  blowing  out  dust,  screwing  on  pump  pipe,  etc. 


66  AN  INTRODUCTION  TO  PSYCHOLOGY 

In  so  far,  then,  as  attention  represents  the  first  step  in 
the  adjustive  act,  we  should  expect  to  find  it  grouping 
together  all  those  elements  in  a  situation  to  which  we  can 
profitably  make  a  single  organized  response. 

For  much  the  same  reason,  we  can  understand  why  at- 
tention dwells  so  briefly  on  any  one  feature  of  a  situation. 
It  is  itself  the  preliminary  stage  of  psycho-motor  adjust- 
ment, and  its  work  is  done  as  soon  as  it  has  stamped  the 
elements  of  a  situation  with  that  kind  of  organized  unity 
to  which  a  response  can  be  made.  It  is,  therefore,  quite 
inevitable  that  attention  should  move  forward  with  con- 
siderable rapidity.  That  we  are  unable  wholly  to  control 
its  behavior  in  this  respect  can  be  readily  shown  by  a  sim- 
ple type  of  test.  Put  a  pencil  dot  on  a  blank  sheet  of 
paper  and  try  to  attend  to  it  uninterruptedly.  So  simple 
a  thing  ought  readily  to  be  retained  in  the  focus  of  the 
field  of  attention.  The  reader  can  easily  convince  himself 
what  actually  occurs  by  making  the  experiment.  An  in- 
structive variant  can  also  be  tried  by  attempting  to  fixate 
for  not  less  than  a  minute  one  of  the  shorter  words  on 
this  page. 

Motor  Aspects  of  Attention. — An  interesting  con- 
firmation of  the  conception  of  attention  we  are  presenting 
is  found  in  a  consideration  of  certain  of  the  motor  accom- 
paniments of  attention.  Clear  vision  is  normally  depend- 
ent upon  an  elaborate  set  of  muscular  acts.  The  eyes  must 
converge  and  the  muscles  controlling  the  lenses  must  be 
innervated  in  order  that  we  may  see  distinctly.  Similarly, 
when  we  are  listening  we  tend  to  turn  the  head  so  as  to 
catch  the  sound  more  distinctly,  and  in  the  case  of  faint 
sounds,  we  hold  our  breath.  Our  animal  ancestors  com- 
monly turn  the  external  ear  to  assist  their  hearing,  an 


ATTENTION  67 

art  which  we  have  largely  lost.  Odor  cannot  be  detected 
unless  the  odorous  substances  are  drawn  up  into  the  nos- 
trils, and  this  is  ordinarily  accomplished  by  a  vigorous 
inhalation.  To  get  the  taste  of  an  object  clearly,  we  press 
it  with  the  tongue  against  the  roof  of  the  mouth.  To  de- 
tect the  contours  or  surfaces  of  an  object,  we  pass  the 
finger  tips  over  it.  In  all  these  cases  a  maximum  of  dis- 
tinctness and  clearness  is  gained  by  motor  activities. 

Less  obvious,  but  not  less  real,  and  probably  not  less 
significant,  are  the  motor  expressions  in  cases  where  we 
are  attending  to  ideas  and  thoughts  rather  than  to  physi- 
cally present  objects.  The  facts  are  here  more  difficult 
of  access,  and  the  reader  must  expect  to  be  left  with  less 
of  certainty  regarding  them.  A  little  observation,  how- 
ever, will  show  that  each  of  us,  when  thinking  hard,  tends 
to  adopt  certain  bodily  attitudes  which  are  more  or  less 
characteristic  and  which  seem  in  some  way  to  aid  the 
thinking.  Some  people  frown  under  these  conditions, 
others  walk  up  and  down,  others  wish  to  be  seated  with 
their  feet  up  in  the  air.  Still  others  bite  their  finger- 
nails, or  tap  with  a  pencil  upon  the  table.  Most  of  these 
performances  are  attributed  merely  to  bad  nervous  habits. 
But  fundamentally  they  are  probably  much  more  than 
that.  They  may  well  represent  protective  devices  to  guard 
the  thinker  against  interruption,  partly  by  putting  him 
into  a  position  of  physical  comfort,  and  partly  by  supply- 
ing him  with  a  group  of  self-controlled  but  reasonably 
vigorous  sensory  stimulations  which  may  perhaps  serve 
to  overwhelm  any  purely  outside  sensory  disturbances.  A 
portion  of  these  reactions  may  be  regarded  as  occasioned 
simply  by  the  overflow  of  unused  nervous  energy,  which 
might  possibly  be  saved  to  advantage.  There  can  be  little 


68      AN  INTRODUCTION  TO  PSYCHOLOGY 

question,  however,  that  whatever  the  individual  history 
by  which  such  muscular  activities  have  been  taken  on, 
their  absence  or  suppression  is  a  source  of  marked  discom- 
fort and  disturbance  to  the  thinker. 

There  is  another  group  of  these  motor  reactions  be- 
longing to  ideational  processes  which  has  a  different  and 
somewhat  more  obvious  explanation.  For  many  people  the 
attempt  to  think  with  closed  eyes  of  some  object  to  the 
right  or  to  the  left  will  occasion  a  movement  of  the  eye- 
balls in  the  corresponding  direction.  Similarly,  to  think 
fixedly  of  a  sound  as  coming  from  a  point  behind  and  to 
one  side  will  produce  in  some  persons  a  strong  tension  in 
the  muscles  of  the  head  and  neck,  if  it  does  not,  indeed, 
occasion  an  actual  turning  of  the  head.  Clearly  this  type 
of  motor  expression  is  simply  a  carrying  over  into  idea- 
tional processes,  as  a  matter  of  habit,  motor  forms  of  be- 
havior which  have  an  evident  adjustive  value  in  the  case 
of  sensory  attention. 

It  is  rather  the  usual  custom  for  psychologists  to  speak, 
as  we  have  already  once  done,  of  these  motor  reactions  as 
'accompaniments'  of  attention.  In  point  of  fact,  while 
they  are  accompaniments  in  a  true  enough  sense,  it  would 
be  a  mistake  to  think  of  them  simply  as  companions  to  an 
entirely  different  process.  It  is  a  truer  view  to  regard 
them  as  in  a  genuine  sense  merely  the  external  expression 
of  the  adjusting  agency  which,  felt  from  within,  is  atten- 
tion. 'The  stretching  out  to  meet'  which  is  the  original 
linguistic  meaning  of  the  term  attention,  is  precisely  and 
exactly  embodied  in  these  preliminary  motor  adjustments 
whereby  we  organize  and  in  a  sense  determine  the  object 
to  which  we  have  to  adjust.  In  the  lower  and  more  reflex 
types  of  reaction,  this  immediate  motor  response  exhausts 


ATTENTION  69 

and  completes  the  adjustment.  In  the  higher  and  more 
conscious  types  of  behavior,  it  simply  sets  the  stage  and 
determines  what  is  the  object  or  the  situation  to  which  in 
a  larger  way  immediate  or  delayed  adjustment  is  to  be 
brought  about. 

Classification  of  the  Forms  of  Attention. — Various 
classifications  of  the  forms  of  attention  have  been  pro- 
posed, a  few  of  which  deserve  brief  mention. 

(1)  An    old    classification    distinguishes    sensory    from 
ideational  attention,  the  former  illustrated  by  any  case  of 
attending  to  sensations  of  color,  sound,  contact,  and  the 
like,   the   latter  exemplified   by  attention  to   a   train   of 
thought.     Obviously  this  division  is  based  on  differences 
in  the  objects  of  attention,  rather  than  on  differences  in- 
side the  attentive  process  itself. 

(2)  Another  distinction  marks  off  immediate  from  de- 
rived attention.    When  a  thing  attracts  the  mind  because 
of  its  intrinsic  interest,  or  its  capacity  to  excite,  attention 
is  immediate.     When  we  attend  because  of  some  second- 
ary  consideration,    attention   is   derived.     To    attend   to 
one's    study    because    one    is    interested    in    high    marks 
affords  an  illustration   of   derived  attention.     Attention 
to  a  thrilling  narrative  will  illustrate  immediate  atten- 
tion. 

(3)  A  distinction  is  often  drawn  between  active  and 
passive  attention.     The  significant  points  in  this  classifi- 
cation are  preserved  and  somewhat  improved  upon  in  the 
division  of  attention  into  three  classes   (a)   spontaneous, 
(b)   involuntary  or  forced  and   (c)   voluntary. 

Spontaneous  attention  is  substantially  synonymous 
with  immediate  attention  and  is  illustrated  in  the  atten- 
tion given  by  babies  to  bright  lights  and  loud  sounds,  by 


70  AN  INTRODUCTION  TO  PSYCHOLOGY 

adults  to  hunger,  to  crowds,  and  to  innate  tastes,  such  for 
example  as  music.  It  is  undoubtedly  the  primitive  form 
of  attention,  out  of  which  the  others  have  grown. 

Involuntary,  forced,  or  passive  attention  is  illustrated 
in  the  compulsion  exercised  over  the  mind  by  very  intense 
sensory  stimulation.  One  may  be  absorbed  in  a  good  book 
(spontaneous  attention)  and  suddenly  be  shocked  into  a 
forced  attention  by  a  clap  of  thunder.  Morbid  ideas  some- 
times intrude  themselves  in  the  same  way. 

Voluntary  attention  (closely  resembling  derived)  is 
represented  by  attention  given  as  the  result  of  definite 
effort.  Anyone  who  succeeds  in  holding  himself  to 
a  distasteful  task  exercises  voluntary  attention  in  this, 
meaning  of  the  term.  This  is  a  form  of  attention  that 
develops  whenever  the  mind  becomes  mature  enough  to 
appreciate  and  entertain  two  conflicting  interests  or  lines 
of  conduct.  Choice  must  be  made.  One  must  be  for  the 
time  at  least  put  aside  and  the  other  encouraged.  Spon- 
taneous attention  early  provides  these  competitive  bidders 
for  attention,  and  voluntary  attention  springs  from  such  a 
soil.  The  effort  to  suppress  disturbing  appeals  to  forced 
attention  obviously  offers  another  field  for  the  develop- 
ment of  voluntary  attention.  Fortunately  for  our  peace 
of  mind,  many  experiences  to  which  we  attend  at  first 
only  with  effort  and  discomfort  become  after  a  little  time 
intrinsically  interesting  and  agreeable,  whereupon  we  give 
them  essentially  spontaneous  attention. 

Analysis  and  Synthesis  in  Attention. — Attention  sub- 
serves two  great  functions  which  psychologists  have  com- 
monly designated  (1)  analysis,  discrimination,  or  dis- 
sociation, and  (2)  synthesis,  or  association.  Every  act  of 
attention  in  a  sense  involves  both  of  these  processes,  al- 


ATTENTION  71 

though  at  any  given  moment  one  or  the  other  generally 
seems  to  be  dominant. 

As  the  reader's  eye  passes  across  this  page  he  will,  in 
the  very  act  of  reading,  necessarily  separate  the  printed 
letters  into  words  to  which  he  attends  either  singly  or 
in  groups.  That  his  attention  is  given  to  the  separate 
words  at  all  instead  of  to  the  shape  of  the  page,  the  color 
of  the  paper,  the  details  of  the  background  against  which 
the  book  is  seen,  is  a  consequence  of  the  fact  that  out  of  all 
the  possible  objects  before  his  vision  he  has  selected  those 
special  parts  which  correspond  to  the  words,  and  has  in 
turn  given  his  attention  to  them  in  their  context  rather 
•than  in  isolation.  At  any  given  moment,  vast  numbers  of 
stimulations  are  attacking  the  various  sense  organs. 
Sounds,  colors,  contacts  of  various  kinds,  are  simulta- 
neously impressed  upon  ear,  eye,  and  skin;  and  yet  we 
are  aware  of  only  a  trifling  fragment  of  all  these  stimuli. 
The  organism  selects  from  out  this  great  range  of  possible 
objects  of  attention  those  which  shall  at  any  moment  be 
heeded,  and  neglects  the  rest.  From  the  descriptions  which 
have  preceded,  the  reader  will  readily  comprehend  that 
the  clue  to  an  understanding  of  why  certain  objects  are 
chosen  for  attention  and  others  neglected  is  to  be  found  in 
the  demands  for  adjustment.  The  adjustive  process  can 
hardly  be  carried  out  in  response  to  objects  in  general.  It 
requires  that  now  this  element  in  the  situation  and  now 
that  shall  be  given  consideration.  The  primitive  form  of 
analysis,  discrimination,  or  dissociation,  is  simply  the  iso- 
lating of  a  particular  portion  of  the  environment  to  which 
an  organized  motor  reaction  can  be  brought  to  pass.  One 
cannot  adjust  to  visual  things  in  general,  but  one  may 
make  a  movement  of  the  hand  designed  to  grasp  some  par- 


72      AN  INTRODUCTION  TO  PSYCHOLOGY 

ticular  visual  object.  Similarly  one  cannot  adjust  success- 
fully to  a  miscellaneous  jumble  of  sounds,  but  one  can 
step  back  to  avoid  the  annihilation  foreshadowed  by  the 
screech  of  an  automobile  horn. 

It  should  be  fairly  obvious  from  these  illustrations  and 
the  dozens  of  others  which  will  readily  suggest  themselves, 
that  effective  guidance  of  an  organism  amid  the  vicissi- 
tudes of  a  physical  and  social  world  such  as  that  in  which 
we  live,  necessitates  such  a  selective  analytical  process  as 
we  have  described.  Every  act  of  attention,  when  scruti- 
nized, will  easily  be  seen  to  involve  this  same  type  of  dis- 
crimination, this  same  breaking  up  into  parts  of  the  great 
complex  world  of  objects,  with  their  various  appeal  to. 
smell,  taste,  touch,  sight,  and  hearing.  Our  illustrations 
have  all  been  chosen  from  instances  of  adjustment  to 
sensory  situations,  but  the  same  dissociative  or  analytical 
process  is  to  be  discerned  in  our  attention  to  ideas  of  all 
kinds.  This  fact  is  peculiarly  evident  in  cases  where  we 
are  thinking  intently  in  the  attempt  to  solve  some  difficult 
problem.  In  such  a  case,  our  thinking  is  often  directed  to 
the  analysis  of  the  thoughts  which  present  themselves. 
The  more  intimate  description  of  these  ideational  processes 
will  be  taken  up  later  after  a  study  of  some  of  the  simpler 
phases  of  our  mental  organization. 

Contrary  to  the  formerly  accepted  views,  the  prevalent 
opinion  of  psychologists  today  is  that  the  consciousness  of 
the  new-born  child,  and  presumably  that  of  the  simpler 
organisms,  is  characterized  by  a  somewhat  vague  blending 
or  fusion  of  many  elements,  like  colors  and  sounds,  which 
to  the  adult  appear  clearly  separate  and  distinct.  The 
transition  from  the  conditions  of  infancy  to  intellectual 
maturity  is  in  large  measure  dependent  upon  the  execu- 


ATTENTION  73 

tion  of  these  acts  of  discrimination  and  analysis  just  de- 
scribed. 

Conditions  of  Discrimination. — We  know  with  great 
certainty  that  colors  are  at  first  distinguished  from  one  an- 
other by  babies  imperfectly  or  not  at  all.  There  is  similar 
evidence  for  believing  that  the  components  of  many  sounds 
are  thus  undistinguished;  and  in  general  there  is  good 
reason  to  suppose  that  at  the  outset  of  life  an  indefinite 
number  of  sensations  may  fuse  together,  provided  only 
that  the  stimulations  occasioning  them  fall  simultaneously 
upon  the  sense  organs.  Even  in  adult  life  certain  of  these 
fusions  persist  in  the  most  obstinate  manner.  Apparently 
only  those  sensations  separate  which  are  forced  to  do  so 
by  the  exigencies  of  adjustment.  For  example,  owing  to 
the  proximity  of  the  sense  organs  and  the  character  of  the 
stimuli  affecting  them,  it  comes  about  that  a  large  propor- 
tion of  the  food  substances  stimulate  both  the  organs  of 
taste  and  those  of  smell.  The  supposedly  characteristic 
tastes  of  many  familiar  beverages  and  foods  are  as  a  mat- 
ter of  fact  due  to  sensations  of  smell  and  not  to  taste  at  all. 
Coffee,  tea,  onions,  apples,  and  asparagus  lose  almost  all 
their  more  agreeable  and  individualistic  features,  if  by 
reason  of  a  cold  or  by  artificial  stoppage  of  the  nostrils, 
one  is  prevented  from  getting  any  odor  sensations.  Other 
instances  o±  fusions  which  persist  even  in  adult  life  may 
readily  be  found  in  the  combinations  with  one  another  of 
pressure  and  temperature  sensations  from  the  skin,  and  of 
both  with  sensations  of  movement  originating  in  the  mus- 
cles, tendons,  and  joints. 

We  have  already  mentioned  the  belief  that  only  such 
sensations  separate  as  are  forced  to  do  so,  but  the  condi- 
tions under  which  auch  dissociation  may  be  brought  about 


74      AN  INTRODUCTION  TO  PSYCHOLOGY 

remain  to  be  stated.  If  a  sensation  or  group  of  sensations 
is  to  be  separated  out  from  a  larger  matrix  so  that  we  may 
adjust  to  it  independently,  it  is  apparently  necessary  that 
it  shall  be  experienced  alone  or  in  a  different  group.  We 
may  express  this  in  a  symbolic  way  by  supposing  that  three 
sensations,  x,  y,  and  z,  occur  together.  The  principle 
formulated  would  require  that  if  x  is  to  be  successfully 
analyzed  out  of  the  compound  it  shall  be  either  experi- 
enced alone  or  in  some  other  group,  such  as  xrs.  In  the 
case  of  colors,  for  example,  this  would  mean  that  if  red, 
blue,  and  green  were  always  experienced  together,  they 
would  presumably  never  be  differentiated,  and  the  pre- 
condition of  their  dissociation  from  one  another  is  that 
they  shall  be  experienced  singly  or  in  other  combinations. 
If  we  translate  this  formula  into  terms  of  nervous  activity, 
we  shall  see  that  it  means  that  we  can  only  discriminate 
differences  when  the  nervous  circuits  involved  are  differ- 
ent. Obviously  the  changing  conditions  in  the  physical 
world  must  speedily  bring  about  the  necessary  variety  in 
the  combination  of  sense  stimulations  required  by  this 
theory  of  analysis  in  order  satisfactorily  to  explain  our 
actual  success  in  discrimination.  It  need  hardly  be 
pointed  out  that  at  an  early  stage  of  its  development  the 
human  organism,  at  least,  secures  the  power  to  bring 
about  artificially  many  of  these  conditions  of  changed 
stimulation  by  its  control  over  its  own  movements.  It  is 
thus  possible,  for  example,  by  pinching  the  nostrils,  to  cut 
off  the  larger  part  of  our  odor  sensations  and  thus  experi- 
mentally to  split  up  the  smell-taste  fusion  to  which  we  have 
referred. 

Reciprocal  Relations  of  Association  and  Dissociation. 
— Every  process  of  analysis  may  from  one  point  of  view  be 


ATTENTION  75 

thought  of  as  an  act  of  synthesis  or  association.  The  men- 
tal process  by  which  one  distinguishes  the  black  and  white 
colors  on  this  page  is  one  in  which,  by  the  very  nature  of 
the  case,  the  two  qualities  thus  distinguished  are  brought 
together  and  associated  with  one  another.  Analysis  and 
synthesis  are,  therefore,  conjoint  processes  involved  in 
every  act  of  attention.  Nor  does  this  tell  the  whole  story. 
When  one  gives  his  attention  to  a  word  on  this  page,  his 
mental  act  unites  into  a  single  mental  whole,  each  of  the 
letters  which  goes  to  make  it  up.  The  process  of  dissociat- 
ing the  word  from  the  rest  of  the  field  of  vision  is  one 
whereby  the  components  of  the  word  are  also  integrated 
into  a  single  object.  It  will  be  found  that  this  conception 
is  applicable  to  all  types  of  organic  adjustment. 

Analysis  and  synthesis,  association  and  dissociation,  are 
thus,  as  it  were,  the  two  blades  of  the  scissors  which  we 
call  attention.  Both  are  invariably  involved  in  every  at- 
tentive act.  Sometimes -we  are  more  interested  from  the 
practical  point  of  view  in  analysis ;  sometimes  in  synthesis. 
But  in  either  case  our  actual  mental  procedure  depends 
upon  the  employment  of  both. 


CHAPTER  VI 
SENSATION 

In  the  account  of  adjustive  processes  we  have  constantly 
referred  to  the  fact  that  man  is  supplied  with  sensitive 
organs  which  are  capable  of  responding  to  various  kinds  of 
physical  stimulations.  Light,  heat,  sound,  contact,  are 
illustrations  of  the  stimuli  to  which  the  organism  is  able 
to  react.  No  doubt  there  are  many  forms  of  physical 
action  to  which  we  are  entirely  insensitive.  Magnetism 
is  an  example  of  such  a  force,  for  which  we  have  no  appro- 
priate receptor.  Connected  with  the  use  of  these  sense 
organs,  are  the  most  rudimentary  of  our  mental  processes, 
and  it  is  therefore  natural  that  we  should  begin  our  more 
exact  analytical  study  of  the  mind  at  this  point. 

The  Development  of  Sense  Organs. — If  we  turn  to 
evolutionary  history,  we  find  that  our  equipment  of  sensory 
organs  presents  a  most  interesting  picture  of  the  develop- 
ment of  highly  specialized  senses  out  of  a  very  crude 
general  sensitivity.  The  simpler  organisms,  like  the 
amoeba,  are  more  or  less  sensitive  to  the  various  forms  of 
stimulation  which  affect  human  beings,  e.g.,  light,  tempera- 
ture, contact,  but  there  are  no  specific  sense  organs  of 
any  kind.  As  we  pass  up  the  scale  in  animal  life,  we  find 
the  rudimentary  vestiges  of  the  specialized  organs  which 
later  become  the  eye,  the  ear,  and  the  other  senses.  These 
present  the  most  varied  assortment  of  devices  for  accom- 
plishing their  purposes.  The  eye,  for  example,  which  makes 

76 


SENSATION  77 

its  first  appearance  as  a  little  pigmented  speck  on  the  sur- 
face of  the  organism,  passes  through  a  great  number  of 
different  forms  before  it  takes  on  the  character  of  the 
highest  vertebrate  eye,  like  that  of  man,  with  its  system  of 
lenses  for  bringing  light  to  a  focus  upon  the  surface  of 
the  retina.  There  is,  moreover,  very  considerable  varia- 
tion in  the  structure  of  the  eye  in  different  vertebrate 
forms  like  the  fishes,  the  birds,  and  the  mammals. 

The  other  sense  organs  display  a  similar  evolutionary 
history,  although  some  of  them,  like  the  ear,  have  de- 
veloped very  much  further  away  from  their  primitive 
forms  than  have  others,  such  as  those  of  contact  and  tem- 
perature. We  may  conveniently  begin  our  study  of  the 
sensory  processes  with  vision. 

The  Organ  of  Vision  and  Its  Stimuli. — A  complete 
knowledge  of  vision  implies  a  detailed  acquaintance  with 
the  anatomy  and  physiology  of  the  eye.  Evidently,  under 
the  present  conditions,  we  must  forego  any  exhaustive 
study  of  the  subject,  and  content  ourselves  with  relatively 
rough  impressions  such  as  can  be  secured  in  the  time  at 
our  disposal. 

The  stimulus  to  vision  consists  normally  of  light  waves 
constituting  the  sunlight  spectrum  from  red  to  violet. 
These  waves  vary  in  rate  from  approximately  435  to  769 
billions  a  second.  An  electrical  current  passed  through  the 
head  will  also  produce  sensations  of  light,  as  will  a  violent 
blow.  The  light  stimulations  are  classified  as  either  homo- 
geneous or  mixed.  Homogeneous  light  is  made  up  of 
waves  of  approximately  equal  vibration  rate  and  equal 
length,  and  is  represented  by  the  pure  colors  of  the  spec- 
trum, such  as  red,  blue,  green.  Mixed  light  finds  its  most 
frequent  exemplification  in  the  ordinary  white  light  of  the 


78  AN  INTRODUCTION  TO  PSYCHOLOGY 


,Pr.  oil. 


'onj. 


Chor. 
Scler. 


Fov.  c. 


Fio.  23. — Horizontal  section  showing  Opt.,  fibers  of  the  optic  nerve 
entering  the  back  of  the  left  eyeball  to  spread  over  its  inner 
surfaces;  Fov.  c.,  fovea  centralis,  the  point  of  most  acute  vision 
in  the  retina  on  which  are  centered  rays  of  light  from  any  ob- 
ject at  which  one  is  looking.  Only  cones  occur  in  this  region. 
Scler.,  the  sclerotic  coat,  tough  and  opaque,  transformed  on  its 
anterior  surfaces  into  the  transparent  cornea.  Chor.,  the  choroid 
coat,  carrying  blood  vessels  and  a  heavy  dark  pigment  Ret., 
the  retina,  terminating  at  a  little  distance  from  the  lens. 
Pr.  til.,  the  cilary  muscle  processes  which  control  the  convexity 
of  the  lens.  The  ligament  in  which  the  lens  is  suspended  may 
be  seen,  just  under  the  letter  "  p,"  which  marks  the  posterior 
chamber  behind  the  iris  and  Cam.  ant.,  the  anterior  chamber, 
both  filled  with  aqueous  humour.  Corpus  vitreum,  the  humour 
of  the  main  cavity  of  the  eyeball.  Con;  ,  the  conjunctiva,  a  very 
thin  mucous  membrane.  (After  James.) 


SENSATION  79 

sun.  As  a  matter  of  fact,  there  is  always  under  ordinary 
conditions  of  vision  an  appreciable  amount  of  mixed  light 
even  when  we  are  looking  at  the  simple  colors.  To  the 
homogeneous  lights  we  owe,  then,  the  various  distinguish- 
able hues  of  the  spectrum  (each  one  corresponding  to  a 
particular  wave  length  or  vibration  rate),  and  to  mixed 
light  the  series  of  colors  from  white  through  gray  to 
black.  The  amplitude  of  the  light  vibration  determines  the 
intensity  of  the  resulting  sensation. 

Figure  23  represents  a  vertical  section  front  to  back 
through  the  center  of  the  human  eye.  It  reveals,  with 
reasonable  clearness,  all  the  more  important  structures. 
The  eye  is  a  roughly  spherical  camera,  into  which  light  is 
admitted  through  a  small  aperture  at  the  center  of  the 
front  surface.  The  general  form  of  the  eye  is  preserved 
by  the  sclerotic  coat,  the  tough  outer  covering  of  the  eye, 
which  is  transparent  on  its  front  surfaces,  known  as  the 
cornea.  Inside  it  is  the  choroid,  a  dark  pigmented  coat 
absorbing  light  rays  and  carrying  many  blood  vessels. 
The  rays  of  light  are  bent  or  refracted  by  the  spherical 
surface  of  the  cornea  and  again  by  the  surfaces  of  the 
lens,  so  that  they  come  together  upon  the  retina,  lying  just 
inside  the  choroid,  to  form  a  well-defined  image,  such  as 
appears  on  the  photographic  plate  of  a  camera  when  the 
lens  is  properly  focused  upon  its  object.  Unless  this 
image  is  clear  and  sharp,  vision  will  be  blurred.  In  the 
photographic  camera,  the  focus  is  adjusted  by  moving  the 
plate  toward,  or  away  from,  the  lens,  as  may  be  required. 
In  the  eye,  the  distance  between  the  lens  and  the  plate,  i.e., 
the  retina,  is  fixed  and  unchangeable.  The  focusing  is  in 
this  case  brought  about  by  an  extremely  ingenious  device. 
The  lens  is  an  elastic,  gelatinous  structure  of  spherical 


80      AN  INTRODUCTION  TO  PSYCHOLOGY 

form,  enclosed  in,  and  suspended  by,  a  very  thin  trans- 
parent membrane.  This  bag-like  membrane  is  attached  to 
muscular  tissue  on  the  inner  surface  of  the  eye-ball.  By 
the  contraction  or  relaxation  of  these  muscles  the  mem- 
brane is  rendered  more  or  less  taut.  As  a  result  of  this 
change  of  tension,  the  lens  is  made  more  or  less  convex, 
more  or  less  spherical  in  shape.  Anyone  familiar  with  the 
manner  in  which  lenses  bend  or  refract  the  rays  of  light 
passing  through  them  will  understand  that  this  changing 
convexity  permits  the  securing  of  clearly  focused  images 


FIG.  24. — Sketch  to  illustrate  the  mechanism  of  accommodation.  A, 
the  lens  accommodated  for  a  near  object,  its  anterior  surface 
advanced ;  B,  the  lens  at  rest,  accommodated  for  a  distant  object. 
C,  the  ciliary  muscles  controlling  the  ligament,  L.,  supporting 
the  lens;  c,  the  cornea;  &,  the  anterior  chamber;  D,  the  vitreous 
humour  of  the  main  cavity  of  the  eyeball.  (After  McKendrick 
and  Snodgrass. ) 


on  the  retina,  just  as  readily  as  is  the  case  in  the  photo- 
graphic camera,  where,  the  lens  remaining  stationary,  the 
plate  is  moved  to  and  fro.  The  more  convex  the  lens,  the 
more  sharply  the  rays  are  bent,  and  the  more  quickly  they 
come  to  a  focus.  As  an  object  approaches  the  eye,  the  lens 
must  become  more  and  more  convex,  if  the  image  of  the 
object  is  to  remain  sharply  focused  upon  the  retina.  (See 
Fig.  24.) 

The  Retina. — The  central  part  of  the  retina,  upon  which 
these  images  fall,  is  known  as  the  fovea,  and  is  the  region 
of  clearest  vision  in  the  eye.  It  is  characterized  by  a  slight 


SENSATION  81 

depression  and  the  presence  of  a  slightly  yellowish  pig- 
ment. From  the  fovea  toward  the  lens,  the  retina  becomes 
progressively  less  capable  of  affording  clear,  distinct 
vision. 

As  the  sketch  indicates   (Fig.  25),  the  fibers  of  the 
optic  nerve  enter  the  eye-ball  from  its  rear  surface,  and 


FlG.  25. — Horizontal  section  of  right  eye  showing  retinal  fibers 
Nop,  optic  nerve;  8,  sclerotic;  Ch,  choroid;  K,  retina;  /',  blind 
spot,  no  retinal  structure  present;  F,  fovea,  point  of  clearest 
vision  The  retinal  fibers  are  shown  turning  back  to  meet  the 
pigment  layer  of  the  choroid.  The  light  coming  in  through 
the  cornea,  lens  and  optic  humours,  passes  through  the  optic 
fibers  before  it  reaches  the  rods  and  cones  on  the  inner  surfaces 
of  the  retina.  (James  after  Kuss.) 

there  spread  themselves  in  cup-shape,  all  over  the  surfaces 
of  the  inner  part  of  the  eye.  The  fibers  turn  toward  the 
outside  of  the  eye,  and  terminate  in  the  very  complex  struc- 
ture constituting  the  retina,  of  which  Figure  26  gives  a 
vertical  cross-section.  The  actual  sensitive  organs  which 
the  light  stimulates  after  passing  through  the  optic  fibers 
and  the  inner  parts  of  the  retina  are  the  so-called  rods 


82 


AN  INTRODUCTION  TO  PSYCHOLOGY 


and  cones,  whose  shapes  explain  the  names  given  them. 
In  the  fovea,  cones  alone  are  found.  In  the  forward  re- 
gions of  the  retina  near  the  lens,  the  rods  are  practically 
alone.  In  the  intermediate  regions,  both  rods  and  cones 
are  found. 


H 


FIG.  26. — The  layers  of  the  retina.  A,  layer  of  rods  and  cones  next 
the  choroid;  a,  rods;  6,  cones.  E,  layer  of  large  bipolar  nerve 
cells;  O,  layer  of  large  ganglion  cells;  H,  layer  of  optic  nerve 
fibers  over  which  nervous  impulses  travel  toward  the  brain  after 
light  has  stimulated  the  rods  and  cones;  8,  a  centrifugal  nerve 
fiber  permitting  impulses  to  reach  the  retina  from  the  brain. 
Unlike  other  sense  organs,  the  retina  is  itself  really  a  portion 
of  the  brain,  pushed  out  to  the  periphery  of  the  body. 

In  the  very  center  of  the  region  where  the  optic  nerve 
enters  the  eye-ball  there  is  no  retinal  structure,  and  in 
consequence  no  vision.  This  is  the  blind  spot,  whose  pres- 
ence can  be  easily  verified  by  closing  the  left  eye,  fixating 


SENSATION  83 

the  other  upon  a  pencil  point  held  some  ten  or  twelve 
inches  directly  in  front  of  the  face  while  one  moves  a 
small  object,  like  a  coin,  slowly  to  the  right  away  from  the 
pencil.  When  about  three  or  four  inches  away  from  the 
point  fixated,  the  object  will  suddenly  disappear,  a  mo- 
ment later  to  appear  again. 

The  retina  is  sensitive  to  colors  in  a  curiously  irregular 
way.  Under  ordinary  daylight  conditions,  only  the  cen- 
tral parts  of  the  retina  in  and  immediately  about  the 
fovea  are  capable  of  reporting  all  the  colors  to  us.  In 
most  individuals  the  regions  lying  thirty  or  more  degrees 
of  arc  away  from  the  fovea  are  incapable  of  giving  us 
sensations  of  red  and  green.  These  two  colors,  when 
they  fall  upon  the  outer  margins  of  the  retina,  are  seen 
as  yellowish,  bluish,  or  grayish,  as  the  case  may  be.  Then 
there  comes  a  zone  in  which  yellow  and  blue,  and  their 
compounds,  together  with  white,  black,  and  gray,  are 
seen,  and  finally  there  is  a  narrow  band  in  the  extreme 
anterior  part  of  the  retina  where  all  colors  are  seen  as 
white,  black,  or  gray,  or  not  seen  at  all.  Meantime,  al- 
though these  peripheral  parts  of  the  retina  are  relatively 
deficient  in  color  vision,  they  are  very  sensitive  to  white 
light  and  to  movement  of  any  kind.  Stars  can  often  be 
seen  in  'indirect  vision'  by  these  peripheral  parts  of  the 
retina,  where  the  rods  predominate,  which  are  invisible  by 
direct  foveal  vision,  where  -the  cones  are  in  charge. 

Binocular  Vision. — We  have  two  eyes,  and  vision  is  a 
binocular  process.  Although  under  some  conditions  we  see 
objects  double,  normally  we  have  single  vision,  and  we 
must  say  a  word  about  the  conditions  which  produce  this 
result.  Each  eye  is  controlled  by  six  muscles,  by  means  of 
which  it  is  moved  right  and  left,  and  up  and  down.  The 


84 


AN  INTRODUCTION  TO  PSYCHOLOGY 


controlling  muscles  are  so  adjusted  that  the  eyes  always 
move  upward  or  downward  together.  They  may  converge, 
that  is,  turn  in,  at  the  same  time,  but  they  may  not  diverge 
beyond  the  position  at  which  their  axes  are  parallel.  The 
practical  upshot  of  these  limitations  upon  the  movements 
of  the  eyes  is  that  when  the  gaze  is  fixed  upon  a  given 


FIG.  27. — The  two  lower  circles  represent  the  retinal  surfaces  of  the 
two  eyes  as  seen  from  behind.  F  is  the  fovea,  B,  the  blind  spot 
where  the  optic  nerve  enters  the  eye.  The  retinae  are  divided 
into  four  quadrants.  Each  quadrant  corresponds  to  its  geo- 
metrically (not  anatomically)  similar  quadrant  in  the  other 
eye,  which  bears  the  same  number.  The  nasal  half  of  one 
retina  corresponds  to  the  temporal  half  of  the  other.  Cor- 
responding points  whose  stimulation  produces  single  vision  are 
located  in  geometrically  similar  quadrants. 

The  upper  part  of  the  diagram  represents  the  eyes  fixated  on  the 
point  F  whose  images  fall  on  the  two  foveal  regions  ff  and 
produce  single  vision.  0  is  the  optic  nerve.  Rays  of  light 
from  such  points  as  E  and  l>  fall  on  the  corresponding  points 


SENSATION  85 

point,  the  rays  of  light  proceeding  from  it  are  brought  to 
a  focus  upon  the  fovea  of  the  two  eyes,  and  the  image  of 
the  entire  object  at  which  one  is  looking  is  distributed 
over  each  retina  in  such  a  way  that  geometrically  similar 
regions  are  stimulated  by  rays  from  any  given  point. 
Single  vision  apparently  results  wherever  this  occurs. 
Figure  27  will  illustrate  the  statement  just  made.  If 
the  retina  of  the  right  eye  were  lifted,  moved  across,  and 
without  rotation  superposed  upon  the  retina  of  the  left 
eye,  quadrant  UN  would  be  over  quadrant  UT,  'quadrant 
LT  over  quadrant  LN,  etc.  A  pin  put  through  any  part  of 
any  quadrant  would  then  mark  what  are  known  as  cor- 
responding points,  and  these  are  points  which  when  stimu- 
lated together  normally  produce  single  vision.  The  stimu- 
lation of  other  points  produces  either  double  vision  or 
blurred  vision.  No  doubt  the  fact  that  approximately  one 
half  of  the  fibers  of  the  optic  nerve  of  each  eye  cross  over 
and  join  fiber  tracts  from  the  corresponding  region  of  the 

ee  and  dd  and  also  produce  single  vision.  Such  a  line  as  EFD, 
or  it  may  be  a  surface,  all  of  whose  points  are  seen  as  single, 
is  known  as  a  horopter.  When  the  eyes  are  fixated  on  F, 
points  like  B  and  C,  which  lie  respectively  behind  and  in  front 
of  F,  are  seen  double.  The  rays  proceeding  from  them  will 
be  found  in  non-corresponding  quadrants  of  the  retinae  at  bb 
and  cc.  The  rays  from  B  fall  at  b  and  b  which  are  both  inside 
the  foveal  points,  whereas  c  and  o  are  both  outside  these  points. 
The  former  produce  '  homonomously,'  the  latter  '  heteronom- 
ously,'  doubled  images. 

If  in  the  experiment  suggested  on  page  36  an  assistant  pass  a 
screen  in  front  of  one  of  the  eyes,  the  double  image  on  the 
same  side  as  the  screen  will  disappear  when  the  nearer  object 
is  fixated.  This  is  the  case  of  a  '  homonomous '  image.  The 
image  on  the  side  opposite  to  the  screen  (i.e.,  heteronomous) 
will  disappear  when  the  farther  object  is  fixated. 

Such  a  figure  as  the  prism  EXD  illustrates  in  an.  extreme  form  the 
facts  of  binocular  stereoscopic  vision.  The  right  eye  sees  only 
the  surface  XD.  the  left  eye  only  EX.  The  figure  as  seen  by 
both  eyes  appears  as  a  solid.  Ordinarily  there  is  a  field  com- 
mon to  both  eyes  as  in  looking  at  a  sphere. 


86 


AN  INTRODUCTION  TO  PSYCHOLOGY 


other  eye  on  their  way  to  the  occipital  cortex  of  the  brain 
(Fig.  28)  bears  on  this  matter  of  single  vision  from  cor- 
responding points.  If  one  holds  up  two  pencils  in  the 


TFL 


NFR 


LO     RO 


FIG.  28. — Diagram  of  the  optic  pathway.  R,  the  right  eye,  L,  the 
left;  T,  J\,  N,  JV,  the  temporal  and  nasal  halves  respectively 
of  the  left  and  right  retinae;  TFL,  the  temporal  field  of  view 
of  the  left  eye,  seen  by  the  nasal  half  of  that  eye;  NFR,  the 
nasal  field  of  view  of  the  right  eye  seen  by  the  temporal  side 
of  the  retina;  C,  the  optic  chiasma;  OFR,  optic  fibers  from  the 
right  half  of  each  retina  (i.e.,  right  temporal,  left  nasal)  pass- 
ing through  LOG,  the  lower  visual  centers  in  the  geniculate 
bodies  and  the  corpora  quadrigemina,  to  RO,  the  occipital  cor- 
tex of  the  right  half  of  the  cerebrum.  OFL,  fibers  from  the 
left  halves  of  the  two  retinae  proceeding  similarly  to  LO,  the 
left  side  of  the  cerebral  occipital  cortex.  Obviously  destruc- 
tion of  one  side  of  the  visual  cortex,  or  of  the  optic  pathway 
anywhere  above  C,  will  produce  blindness  to  one  half  of  the 
field  of  view  (hemianopsia)  by  destroying  vision  in  one  half  of 
each  retina.  (Modified  from  Seguin.) 

median  plane  of  the  face,  one  about  four  inches  from  the 
eyes  and  the  other  fifteen  or  twenty,  it  will  be  very  easy 
by  fixating  the  further  pencil,  to  see  the  other  one  double. 


SENSATION  87 

Fixation  of  the  nearer  one  will  similarly  produce  doubling 
of  the  further  one.  In  this  case,  the  images  of  the  doubled 
object  are  falling  upon  dissimilar  regions  of  the  two 
retinae. 

Classification  of  Color  Sensations. — Turning  now  to  a 
more  immediate  analysis  of  the  color  qualities  of  vision, 
we  remark  at  once  that  our  optical  sensations  fall  into 
two  great  natural  groups,  to-wit,  those  of  the  achromatic, 
or  black-white-gray  series,  corresponding  to  mixed  light 
waves,  and  those  of  the  chromatic  series,  i.e.,  the  spectral 
colors,  from  red  to  violet,  corresponding  to  pure  homo- 
geneous waves.1  Psychologists  and  painters  have  varied 
somewhat  in  their  view  regarding  the  number  of  so-called 
elementary  colors.  It  was  early  observed  that  by  taking 
a  few  primary  colors,  all  the  others  could  be  produced 
through  mixture,  but  one  is  by  no  means  rigidly  confined 
to  one  group  of  colors  in  selecting  these  'primes.'  More- 
over, the  results  which  one  secures  depend  very  largely 
on  the  methods  chosen  for  making  the  mixtures.  Yellow 
and  blue,  if  mixed  in  certain  pigments,  produce  green, 
whereas  if  they  are  mixed  by  reflection  or  by  rotating 
disks,  they  produce  gray. 

Common  language  recognizes  seven  distinct  shades  in  the 

1  A  curious  phenomenon  sometimes  made  the  basis  of  a  classifi- 
cation of  visual  processes  is  found  in  the  difference  between  '  twi- 
light '  and  daylight  vision.  When  the  spectrum  is  viewed  in  full 
sunlight,  the  brightest  region  is  in  the  yellow.  When,  however,  by 
remaining  for  a  time  in  the  dark  the  retina  has  been  adapted  to 
very  subdued  lights,  the  green  and  the  blue  appear  brighter  than 
the  yellow;  and  if  the  light  is  progressively  made  dimmer,  the  blue 
end  of  the  spectrum  can  be  discerned  after  the  red  end  has  dis- 
appeared. Seen  in  a  faint  light,  therefore,  the  spectrum  appears  as 
a  series  of  bands  of  gray  with  the  brightest  region  in  the  green- 
blue  zone. 


88 


AN  INTRODUCTION  TO  PSYCHOLOGY 


sunlight  spectrum,  i.e.,  red,  orange,  yellow,  green,  light 
blue,  indigo  blue,  and  violet.  Psychologists  have  generally 
maintained  that  there  are  only  four  genuinely  different 
colors  in  the  spectral  group,  to-wit,  red,  yellow,  green,  and 
blue.  Orange  is  alleged  to  be  an  obvious  compound  of 
red  and  yellow.  Violet  is  held  to  be  similarly  an  obvious 
compound  of  blue  and  red.  When  one  adds  a  little  more 
red,  one  procures  a  shade  of  purple,  and  if  the  process  be 
continued,  the  blue  is  finally  altogether  overcome,  and  we 
get  back  to  red.  Moreover,  each  of  these  spectral  hues 


FIG.  29. — The  color  pyramid.  The  line  WB  corresponds  to  the 
white-black  series  of  colors;  the  plane  Bl.RYG  represents  the 
most  saturated  spectral  colors,  e.g.,  blue,  red,  green.  The 
lines  joining  W  and  B  with  the  letters  representing  the  several 
spectral  colors,  e.g.,  Bl.  represent  all  the  transitional  tints  from 
blue  through  pale  blue  to  white,  and  all  the  shades  through 
the  dark  blues  to  black.  (After  Ebbinghaus. ) 

may  be  more  or  less  'saturated.'  We  can  thus  start  with 
red  and  by  adding  more  and  more  white  produce  a  series 
of  pinks,  or  by  adding  increasing  amounts  of  black,  we 
can  produce  a  series  of  deepening  browns.  Figure  29 
exhibits  these  relations.  It  will  be  recognized,  too,  that 


' 

SENSATION  89 

colors  vary  in  brightness  as  well  as  in  saturation  and 
chroma  or  hue. 

Whatever  view  be  taken  regarding  the  number  of  the 
elementary  spectral  qualities,  there  are  some  very  inter- 
esting relations  among  them  which  definitely  affect  our 
color  vision,  and  to  which  brief  reference  may  be  made. 

Color  Mixtures. — When  colored  lights  (not  pigments)1 
are  mixed  together,  new  colors  are  produced  in  accordance 
with  definite  principles  which  can  be  formulated.  For 
example,  red  and  yellow  will  produce  orange,  blue  and  red 
will  produce  violet  or  purple,  and  all  the  combinations 
can  be  readily  ascertained.  One  of  the  most  interesting 
of  these  mixtures  is  that  of  the  so-called  complementary 
colors,  which  when  combined  produce  gray.  Every  color 
in  the  spectrum  has  a  complementary,  also  in  the  spectrum, 
except  green.  Yellow,  if  combined  with  blue,  produces  a 
whitish  gray  when  pigmented  papers  rotated  on  a  color 
wheel  are  used  as  the  source  of  the  colors.  Red  and  blue- 
green  similarly  produce  gray,  but  green  must  be  combined 
with  colors  from  the  two  ends  of  the  spectrum,  i.e.,  red  and 
blue,  or  violet.  Figure  30  exhibits  these  relationships 
graphically. 

Color  Contrast. — There  are  other  color  phenomena  which 
also  serve  to  show  the  intimate  relations  of  these  comple- 
mentary colors  to  one  another.  Color  contrast  is  one  of 
these.  If  a  patch  of  yellow  be  placed  beside  or  upon  a  field 
of  blue,  and  the  eye  be  focused  upon  a  point  where  the  two 
join,  it  will  presently  be  noticed  that  along  the  margin  of 
junction  the  two  colors  are  very  much  more  brilliant  and  of 
deeper  hue  than  elsewhere.  The  reason  for  this  will  be  ex- 

1  Pigment  mixtures  produce  different  results.  They  depend  on  the 
effects  of  light  absorption  and  can  of  course  be  formulated. 


90 


AN  INTRODUCTION  TO  PSYCHOLOGY 


plained  in  a  moment  in  connection  with  a  brief  account  of 
after-images.  Meantime,  if  instead  of  placing  the  yellow 
in  immediate  contact  with  blue,  some  other  color,  like  red, 
or  green,  be  selected,  a  different  and  less  intense  result  is 
produced.  The  maximal  effect  of  this  kind  is  produced 
by  complementary  colors  upon  one  another.  This  type  of 


BED 


FIG.  30. — Colors  at  opposite  ends  of  any  diameter  of  the  circle  pro- 
duce gray,  if  mixed  with  one  another.  Purple,  which  is  the 
complementary  color  to  green,  is  not  found  in  the  spectrum, 
but  is  produced  by  a  mixture  of  the  end-colors  of  the  spectrum, 
red  and  violet.  Colors  opposite  blank  segments  are  alleged  to 
be  psychologically  pure  and  elementary;  i.e.,  they  do  not  sug- 
gest other  colors.  Some  colors  like  orange  distinctly  suggest 
other  hues,  e.g.,  in  this  case  red  and  yellow.  Colors  opposite 
shaded  segments  are  of  this  composite  character. 

contrast  is  sometimes  spoken  of  as  successive  contrast,  the 
eye  passing  from  one  color,  which  has  been  fixated,  on  to 
another.  The  visual  quality  of  the  latter  is  sure  to  be 
affected  by  the  preceding  retinal  stimulation. 

Simultaneous  contrast  is  a  name  for  a  color  phenomenon 


SENSATION  91 

less  often  observed  in  ordinary  experience,  but  in  some 
ways  much  more  striking  when  encountered.  If  two  small 
patches  of  the  same  gray  paper  be  placed  the  one  upon  a 
blue  field  and  the  other  upon  a  yellow  field,  the  first  will 
take  on  a  yellowish,  and  the  other  a  bluish  tinge.  If  a  thin 
piece  of  white  tissue  paper  be  spread  over  both  colored 
surfaces,  it  Avill  be  quite  impossible  to  convince  any  un- 
informed observer  that  the  patches  are  actually  pure  gray, 
much  less  that  they  really  match  one  another.  This 
tendency  of  a  colored  surface  to  induce  a  complementary 
shade  upon  any  small  colorless  area  within  its  boundaries 
gives  striking  evidence  again  of  the  interdependence  of 
complementary  colors. 

After-images. — It  is  true  in  the  case  of  all  the  senses 
that  a  stimulus  exercises  an  effect  upon  the  sense  organ 
which  somewhat  outlasts  its  actual  contact  with  the  organ. 
Vision  affords  the  most  conspicuous  instance  of  this  fact 
in  the  so-called  after-images,  which  ought,  perhaps,  rather 
to  be  called  'after-sensations.'  These  are  of  two  main 
kinds,  the  positive  and  the  negative.  If  the  eye  be  closed 
for  a  few  moments,  and  then  opened  and  fixated  for  an 
instant  upon  an  electric  light,  and  at  once  closed  again, 
there  will  be  seen  for  some  little  time  thereafter  a  distinct 
image  of  the  light,  and  at  first  with  an  intensity  only 
slightly  less  than  that  of  the  objective  sensation.  This  is  an 
example  of  the  positive  after-image.  It  takes  its  name 
from  the  photographic  positive  plate,  in  which  the  relations 
of  light  and  shade  and  color  are  as  in  the  object  itself. 
The  positive  image  is  due  simply  to  the  continuation  of  the 
retinal  excitement  after  the  removal  of  the  stimulus.  The 
negative  image  involves  a  reversal  of  these  light  and 
color  relations.  If  the  eye  be  fixated  upon  a  point  in  the 


92  AN  INTRODUCTION  TO  PSYCHOLOGY 

center  of  a  small  red  field  for  fifteen  or  twenty  seconds, 
and  then  turned  upon  some  neutral  colored  field,  or  closed, 
there  will  presently  emerge  a  bluish-green  image  cor- 
responding to  the  red  object  originally  fixated.  In  gen- 
eral it  will  be  found  that  in  the  negative  image  all  colors 
are  complementaries  of  the  colors  in  the  stimulus,  and  the 
relations  of  light  and  shade  will  be  inverted;  what  was 
light  in  the  object  will  be  dark  in  the  after-image,  and 
vice  versa. 

Color-Blindness. — Attention  was  called  at  an  earlier 
point  in  the  chapter  to  the  fact  that  the  peripheral  por- 
tions of  the  normal  retina  are  more  or  less  color-blind. 
Some  persons  suffer  from  a  form  of  color-blindness  which 
affects  the  entire  retina.  This  is  a  difficulty  which  seems 
much  more  common  in  men  than  in  women.  It  is  hardly 
practicable  to  describe  pathological  color-blindness  in  de- 
tail at  this  point.  Suffice  it  to  say  that  in  or  of  the  com- 
moner types  the  spectrum  is  seen  as  half  }  owish  and 
half  greenish.  The  region  of  the  green  itself  is  in  these 
cases  often  seen  as  gray.  Persons  belonging  to  this  group 
are  said  to  be  red-green  blind.  In  general,  it  may  be  added 
that  like  the  peripheral  color-blindness  of  the  normal  eye, 
pathological  color-blindness  suggests  that  the  color  pairs 
red  and  green,  blue  and  yellow,  and  black  and  white,  re- 
spectively, belong  together  as  more  or  less  distinct  parts 
of  color  vision. 

Theory  of  Color  Phenomena. — Many  different  theories 
of  the  color  sense  have  been  propounded,  but  there  is  as 
yet  none  which  enjoys  universal  acceptance.  In  the 
writer's  opinion,  the  theory  of  Mrs.  Ladd-Franklin  is 
preferable  to  any  of  the  others  at  present  available,  be- 
cause it  presents  fewer  conflicts  with  recognized  facts.  It 


SENSATION  93 

may  be  said,  indeed,  that  all  the  theories  are  simply  at- 
tempts to  formulate  the  several  varieties  of  facts  in  a 
mutually  consistent  way. 

Mrs.  Franklin  assumes  that  vision  was  originally  con- 
fined to  the  qualities  we  now  call  gray,  with  white  at  one 
extreme  and  black  at  the  other.  The  outer  regions  of  the 
retina  still  represent  this  primitive  condition.  As  evolu- 
tion proceeded,  the  chemical  substance  in  the  retina  which 
originally  occasioned  our  sensations  of  gray  has  been  dif- 
ferentiated so  that  it  now  is  stimulated  by  the  various 
spectral  colors,  each  of  which  produces  a  partial  dis- 
integration of  it.  The  first  differentiation  which  occurred 
corresponds  to  the  sensations  of  yellow  and  blue.  It  will 
be  recalled  that  these  colors  are  seen  pretty  well  out 
toward  the  anterior  regions  of  the  retina.  The  last  dif- 
ferentiation corresponds  to  the  colors  red  and  green,  which 
are  seen  over  a  relatively  circumscribed  central  region. 
This  red  and  green  process  she  thinks  of  as  having  de- 
veloped out  of  the  older  yellow  process.  The  explanations 
of  the  several  forms  of  color  phenomena  resemble  in  many 
particulars  those  proposed  by  other  theorists.  We  may 
formulate  some  of  them  very  briefly. 

Color  mixture  is  brought  about  by  the  disintegration  of 
one  or  another  part  of  the  chemical  substance  in  the  retina 
whose  action  directly  stimulates  the  rods  and  cones.  For 
example,  when  red  and  blue  are  combined,,  the  result,  i.e., 
purple,  corresponds  to  a  splitting  off  of  the  red  part  of  the 
red-green  process  and  a  similar  splitting  off  of  the  blue 
of  the  yellow-blue  process.  The  gray  of  complementary 
colors  is  brought  about  by  the  entire  disintegration  of  the 
original  visual  substance,  just  as  occurs  when  white  light 
itself  is  seen.  If,  for  example,  yellow  and  blue  are  mixed, 


94      AN  INTRODUCTION  TO  PSYCHOLOGY 

each  color  disintegrates  a  part  of  the  original  color  sub- 
stance. The  two  together  effect  a  complete  disintegration 
of  it.  After-images  of  the  positive  kind  simply  represent, 
as  in  all  theories,  the  continuation  of  the  original  effects 
of  the  stimulus.  Negative  after-images  are  explained  by 
assuming  that  after  the  eye  has  been  stimulated  for  a 
considerable  time  by  a  color  like  blue,  and  one  portion  of 
the  color  molecules  in  consequence  has  been  shattered, 
there  is  a  tendency,  after  the  blue  is  removed,  for  the  rest 
of  the  molecular  process  to  go  to  pieces  in  its  turn.  In 
this  particular  case  the  secondary  part  of  the  process  rep- 
resents yellow.  Consequently  the  after-image  for  blue  is 
yellow.  Successive  contrast  is  of  course  simply  an  after- 
image effect.  If  the  eye  has  been  fatigued  for  yellow,  and 
is  then  turned  to  look  at  blue,  the  blue  is  seen  as  deeper  and 
more  vivid  than  otherwise,  because  there  is  a  combination 
of  actual  objective  blue  with  a  negative  after-image  blue. 
Contrast  phenomena  are  assigned  to  the  progressive  break- 
ing down  of  the  chemical  substances,  probably  assisted  by 
the  capillary  circulation.  The  gray  patch  in  a  yellow  field 
is  seen  as  bluish,  because  the  molecules  which  the  circula- 
tion carries  across  the  retinal  region  corresponding  to  the 
gray  are  already  disintegrated  as  regards  yellow  and  are 
undergoing  the  process  of  disintegration  which  is  seen  as 
blue. 

Auditory  Sensations. — Psychologists  have  been  wont  to 
divide  auditory  sense  experiences  into  two  great  groups — 
noises  and  tones.  This  is  to  be  regarded  as  a  convenient 
working  division,  rather  than  as  implying  any  hard  and 
fast  distinction.  It  so  happens  that  the  sounds  which  we 
call  tones  arise  from  regular,  periodic  vibrations  of  the 
air,  while  noises  arise  from  non-periodic  vibrations. 


SENSATION  95 

Nevertheless,  most  tones  have  some  accompaniments  of 
noise,  and  many  noises  present  a  distinctly  tonal  char- 
acter. The  sounds  of  a  piano  are  primarily  tones,  but 
the  striking  of  the  hammers  upon  the  wires  produces  al- 
most inevitably  a  noise  which  is  heard  with  the  tone.  The 
rumble  of  cart  wheels  in  the  street  is  a  noise,  but  at  a 
little  distance  there  is  often  a  definite  impression  of  tone. 
Certainly  one  notices  the  change  in  pitch  as  such  a  noisy 
vehicle  disappears  in  the  distance. 

Pitch,  Intensity,  and  Quality  of  Tones. — There  is  a 
relatively  simple  relation  between  our  experiences  of  tone 
and  the  physical  stimulations  occasioning  them.  Thus  the 
pitch  of  a  tone  corresponds  to  the  frequency  of  the  vibra- 
tions. We  begin  to  hear  these  vibrations  as  tone  when 
they  occur  at  the  rate  of  about  sixteen  or  twenty  to  the 
second,  and  we  cease  to  discern  them  as  tones  when  they 
exceed  forty  or  fifty  thousand  to  the  second.  Most  of  our 
musical  experiences  are  comprised  within  a  relatively 
brief  compass,  running  from  about  sixty-four  vibrations 
in  the  second  to  some  four  or  five  thousand. 

While  pitch  corresponds  to  the  rate  or  frequency  of 
vibration,  the  intensity  of  a  tone  corresponds  to  the  ampli- 
tude of  the  vibration.  The  tone  quality  corresponds  to 
the  form  of  the  sound  wave,  as  determined  by  the  number, 
character,  and  relative  intensity  of  the  partial  tones  which 
are  present.  German  writers,  in  particular,  speak  of  tones 
as  clangs,  and  distinguish  between  simple  and  complex 
clangs.  English  writers  sometimes  speak  of  pure  and  mixed 
tones,  or  simple  and  complex  tones.  All  these  terms  are 
designed  to  apply  to  the  same  set  of  facts,  i.e.,  that  a  tone 
may  arise  from  a  vibration  of  a  single  rate,  as  in  the  case 
of  a  tuning  fork,  or  from  a  group  of  vibrations  made  up 


96      AN  INTRODUCTION  TO  PSYCHOLOGY 

of  a  fundamental  tone  with  a  series  of  partial  tones.  In 
the  case  of  a  stretched  string,  for  example,  like  a  piano 
wire,  or  a  violin  string,  there  are  vibrations  corresponding 
not  only  to  the  entire  length  of  the  string,  but  also  to 
segments  of  one-half,  one-quarter,  one-third,  etc.,  of  the 
length  of  the  string.  Each  of  these  segments  occasions  a 
separate  tone  which  blends  with  the  others,  and  the  quality 
of  the  entire  mass  of  sound  will  depend  upon  the  number 
of  these  partial  tones,  or  over-tones,  which  are  present, 
whether  they  harmonize  or  not  with  one  another,  and  how 
strong  each  is  in  relation  to  the  others.  The  peculiar  tone 
quality  of  different  instruments,  e.g.,  the  piano  as  con- 
trasted with  the  cornet,  or  the  flute,  is  entirely  dependent 
upon  this  composition  of  the  sound  waves  given  off. 

The  ability  to  analyze  complex  tones,  or  chords,  depends 
upon  the  capacity  to  pick  out  the  constituent  tones  which 
enter  into  one  of  these  complex  tonal  masses,  and  the 
ability  to  differentiate  and  identify  familiar  combinations 
of  tones  and  noises  depends  on  this  same  trait.  The  human 
voice  is  made  up  of  both  noises  and  tones,  and  spoken 
language  illustrates  this  fact  in  the  most  precise  way. 
The  vowels  are  essentially  tonal  elements  of  speech.  The 
consonants  are  intrinsically  noises.  Each  individual  voice 
represents  a  peculiar  and  characteristic  combination  of 
these  two  elements. 

The  Auditory  Sense  Organ. — Although  the  main  facts 
and  the  general  principles  involved  in  the  anatomy  and 
physiology  of  the  ear  are  quite  capable  of  simple  formula- 
tion, the  minute  anatomy  is  extremely  complicated  and 
difficult  to  follow.  We  can  accordingly  make  no  pretense 
of  any  such  detailed  exposition. 

The  ear  consists  of  three  main  divisions  (see  Fig.  31) ; 


SENSATION 


97 


(1)  the  external  ear,  of  which  the  conch  and  part  of  the 
so-called  meatus  or  passage  is  visible;  (2)  the  middle  ear, 
a  wedge-shaped  cavity  with  the  broad  edge  of  the  wedge 
above,  the  sharp  edge  below,  and  the  long  axis  roughly 


FIG.  31. — Diagram  -of  ear.  A,  auditory  canal  of  the  external  ear; 
B,  tympanic  membrane  separating  the  external  from  the  middle 
ear,  C ;  D,  Eustachian  tube  leading  from  the  middle  ear  to  the 
throat;  E,  one  of  the  semicircular  canals  of  the  internal  ear, 
arising  out  of  the  utricle  upon  which,  as  upon  the  adjacent 
saccule,  fibers  from  the  vestibular  branch  of  the  eighth  nerve 
are  shown  terminating.  The  region  of  the  internal  ear  op- 
posite the  end  of  the  stirrup  bone  is  known  as  the  vestibule. 
F,  the  spiral  of  the  cochlea,  through  the  central  pillar  of  which 
the  auditory  nerve  is  shown  entering  to  spread  out  toward  the 
hair  cells  of  the  cochlear  canal,  as  indicated  in  Figures  32  and 
35;  G,  the  main  trunk  of  the  eighth  nerve.  (After  Hough  and 
Sedgwick. ) 

parallel  with  the  sides  of  the  head.  From  this  a  tube 
leads  down  into  the  throat.  At  the  point  where  the  ex- 
ternal meatus  opens  into  the  middle  ear  a  large  membrane 


98 


AN  INTRODUCTION  TO  PSYCHOLOGY 


fills  up  the  passage.  To  the  center  of  this  membrane  is 
attached  the  first  of  a  chain  of  three  bones  extending  from 
it  across  the  cavity  of  the  middle  ear  to  an  aperture  in 
the  inner  surface  of  the  chamber,  which  opens  into  (3) 


FIG.  32. — Vertical  section  through  the  bones  containing  the  cochlea; 
en,  the  main  trunk  of  the  cochlear  nerve;  g,  ganglion;  st,  scala 
tympani;  sv,  scala  vestibuli;  c,  cochlea  canal.  (After  Gray.) 


O 


EC 


PC 


B 


FIG.  33,  A  and  B. — Sketch  of  left  bony  labyrinth  viewed  from  outer 
side.  In  B  part  of  the  bones  are  cut  away  to  show  the  internal 
cavities.  C,  cochlea;  SC,  superior  semicircular  canal;  EC,  ex- 
ternal canal ;  PC,  posterior  canal ;  AM,  ampulla  of  canal ;  0, 
oval  window  into  which  stirrup  bone  fits;  R,  round  window 
opening  into  the  middle  ear;  ST,  scale  tympani,  connected  with 
It;  8V,  scala  vestibuli,  connected  with  0.  (After  Cunningham.) 

the  internal  ear.  This  last  is  a  very  elaborate  system  of 
tunnels  or  cavities  in  the  solid  bone  of  the  skull,  lined 
throughout  with  an  extremely  irregular  membranous  sac, 


SENSATION  99 

filled  with  fluids  and  supported  upon  appropriate  bony 
structures.  Inside  the  sac  are  mounted  innumerable  little 
hair  cells,  whose  bases  are  in  connection  with  the  minute 
terminations  of  the  sensory  nerve.  See  Figs.  32,  33,  34,  35. 
When  a  sound  wave  reaches  the  ear,  it  first  throws  into 
vibration  the  drum  membrane  separating  the  external 
from  the  middle  ear.  Attached  to  the  center  of  this  mem- 


S      U 


FIG.  34. — Diagram  of  membranous  labyrinth  [supported  within  the 
bony  labyrinth  shown  in  Figure  33],  filled  with  lymph  and  sur- 
rounded by  it.  C,  cochlea;  8,  saccule,  united  by  a  small  duct, 
with  U,  the  utricle,  out  of  which  spring  the  semicircular  canals, 
8C.  The  connection  of  the  nerve  with  the  end  organs  in  the 
membranous  labyrinth  is  indicated  in  Figure  31.  (After  Cun- 
ningham. ) 

brane  is  the  first  of  the  chain  of  bones,  whose  motion  is  in 
turn  transmitted  to  the  other  two  bones  in  the  chain,  and 
thence  by  the  impact  of  the  latter  upon  the  liquid  (found 
both  outside  and  inside  the  membranous  sac)  of  the  in- 
ternal ear,  vibrations  are  set  up  which  stimulate  the  tiny 
hairs  of  the  hair  cells.  At  this  point  originate  the  nervous 
impulses  which,  traveling  back  up  the  auditory  nerve, 
finally  reach  the  .auditory  cortex  of  the  cerebrum  (see 
Fig.  13),  whereupon  a  sound  is  heard. 

The  Semicircular  Canals. — The  vestibular  portions  of 
the  internal  ear  (see  Figs.  31,  34)  may  possibly  have  to  do 


100  AN  INTRODUCTION  TO  PSYCHOLOGY 

with  the  perception  of  noise,  though  this  is  very  doubtful, 
but  the  semicircular  canals  are  organs  for  the  detection  of 
bodily  movement  and  for  the  preservation  of  balance. 
They  have  no  real  auditory  function  at  all.  In  the  primi- 
tive ear  we  find  a  rude  sac  with  little  pebble-like  otoliths 
which,  when  the  organism  is  moved  or  jarred,  strike  against 
the  sensitive  walls  of  the  sac  and  so  give  a  sensory  warning 
signal.  In  man  and  the  higher  animals  this  organ  has  dif- 
ferentiated into  two — the  one  the  cochlear  structure  we 
have  described,  sensitive  primarily  to  air  vibrations  outside 


R.M. 


B.C. 


FIG.  35. — Diagram  of  a  cross  section  of  one  of  the  whorls  of  the 
cochlea.  8.T.,  scala  tympani,  a  lymph-filled  passage  leading 
from  a  round  window,  closed  by  a  membrane,  in  the  wall  of  the 
middle  ear.  This  membrane  permits  some  movement  to  and 
fro  of  the  liquids  of  the  internal  ear,  when  vibrations  are  set 
up  in  them  by  the  air  waves  coming  in  through  the  external 
and  middle  ear.  8.V.,  scala  vestibuli,  a  channel  leading  from 
the  oval  window  in  the  wall  of  the  middle  ear  into  which  the 
base  of  the  stirrup  bone  is  inserted.  These  two  passages,  8.T. 
and  S.V.,  join  one  another  at  the  top  of  the  cochlea.  C.C.,  the 
lymph-filled  canal  of  the  cochlea,  separated  by  R.M.,  Reissner's 
membrane,  from  the  scala  vestibuli  and  by  B.M.,  the  basilar 
membrane,  from  the  scala  tympani.  T.M.,  the  tectorial  mem- 
brane thought  by  some  authorities  to  be  the  body  which  re- 
sponds by  sympathetic  vibrations  to  the  waves  produced  in  the 
endolymph  of  the  ear  by  external  sounds.  The  theory  assumes 
that  the  membrane  strikes  against  tho  tips  of  the  hair  cells 
and  thus  sets  up  nervous  impulses  in  the  .auditory  nerve.  Most 
authorities  think  that  the  basilar  membrane  serves  this  func- 
tion and  transmits  its  vibrations  directly  to  the  hair  cells  rest- 
ing on  it.  I.II.C.  and  O.H.C.,  inner  and  outer  rows  of  hair  cells 
respectively;  8.C.,  supporting  cells;  R.C.,  rods  of  Corti;  A.N.. 
auditory  nerve.  (Modified  from  Stewart.) 


BACKERS   COLL.ERE 
NBARA.    CALIFORNIA 


SENSATION 


the  organism  ;  the  other  the  semicircular  canals  and  the  ves- 
tibular  apparatus,  sensitive  to  gross  movements  of  the  en- 
tire body.  The  three  canals  have  developed  approximately 
at  right  angles  to  each  other  and  corresponding  to  the  three 
main  planes  of  the  body.  Each  is  presumably  most  sensi- 
tive to  movement  of  the  body  in  one  of  these  planes.  Like 
the  vestibular  arrangement,  they  retain  the  old  otolith  de- 
vice. These  otoliths  are  suspended  in  the  liquids  of  the 
membranous  sac  and  when  the  head  or  body  is  moved 
quickly,  they  lag  somewhat  behind  and  come  into  contact 
with  the  hair  cell  terminals  found  in  these  regions,  as  well 
as  in  the  cochlea.  This  sets  up  a  sensory  impulse,  which, 
instead  of  passing  to  the  auditory  cortex  and  so  occasioning 
a  sensation  of  sound,  is  conveyed  over  quite  a  different 
pathway  to  cerebellar  and  other  centers  and  thence  to  cer- 
tain muscle  groups  —  of  the  eyes,  the  head,  and  trunk  —  and 
compensatory  movements  are  released  tending  to  preserve 
bodily  equilibrium. 

It  is  doubtful  whether  under  normal  conditions  the 
semicircular  canals  produce  any  sensations  of  which  we 
are  directly  conscious.  But  if  they  be  violently  stimulated, 
as  in  rapid  whirling,  we  are  made  dizzy.  We  thus  learn 
of  their  action  through  the  sensations  of  vision  and  con- 
tact and  movement,  which  they  reflexly  stimulate,  rather 
than  directly  by  a  conscious  quality  of  their  own.  There 
is  no  question  of  their  practical  importance,  for  if  diseased, 
they  cause  dizziness,  loss  of  balance,  and  general  disturb- 
ance of  motor  coordination. 

Gustatory  Sensations.  —  As  the  result  of  a  good  deal  of 
discussion  and  experimentation,  psychologists  have  come 
generally  to  agree  that  there  are  four,  and  only  four,  ele- 
mentary qualities  of  taste,  i.e.,  salt,  sour,  sweet,  and  bitter. 


102  AN  INTRODUCTION  TO  PSYCHOLOGY 

Some  observers  would  add  to  this  list  metallic  and  soapy 
tastes.  They  are  often  combined  with  one  another  and 
with  sensations  of  temperature,  contact,  smell,  and  move- 
ment. By  means  of  such  combinations  we  have  a  very 
large  number  of  characteristic  tastes  of  foods  and  bever- 
ages which  are,  however,  capable  of  analysis  into  these 
constituents.  Lemonade  in  its  ordinary  forms  obviously 
involves  sour,  sweet,  cold,  and  contact.  Coffee  involves 
bitter,  sweet,  heat,  and  contact.  Both  involve  odor  to  a 
degree  that  the  uninformed  person  is  utterly  unaware  of. 
Everybody  has  observed  that  when  suffering  from  a  cold 
in  the  head  the  tastes  of  foods  are  apt  to  be  dulled.  This 
is  commonly  attributed  to  the  direct  effect  of  inflamma- 
tion and  congestion  of  the  membranes  of  the  mouth.  In 
point  of  fact  it  is  much  more  largely  due  to  the  sup- 
pression of  sensations  of  smell.  By  blindfolding  the  eyes 
and  stopping  the  nostrils,  it  will  be  found  that  the  aver- 
age individual  is  quite  at  a  loss  to  identify  many  of  the 
common  food  substances,  and  if  the  further  precaution  be 
taken  of  reducing  them  to  fluid  form  and  presenting  them 
at  the  temperature  of  the  mouth,  it  will  be  found  that 
only  the  four  qualities  already  mentioned  can  as  a  rule  be 
detected,  and  even  for  them  there  is  often  great  uncertainty. 

There  are  several  kinds  of  evidence  tending  to  confirm 
the  really  elementary  character  of  these  four  tastes.  One 
of  them  is  indicated  in  the  suggestion  above.  If  the 
stimuli  are  all  made  of  uniform  temperature,  and  reduced 
to  fluid  form  with  the  elimination  of  smell,  there  is  almost 
never  a  tendency  to  mention  any  other  kind  of  taste  qual- 
ity. These  four  seem  to  every  observer  adequate. 

It  is  commonly  supposed  that  the  various  taste  sensa- 
tions may  be  experienced  on  any  part  of  the  tongue.  As  a 


SENSATION 


103 


matter  of  fact,  the  center  of  the  tongue  is  very  little  sensi- 
tive to  taste,  and  the  marginal  regions  differ  decidedly 
from  one  another  in  the  kind  of  sensitivity  possessed. 
(Fig.  36.)  Thus  the  tip  of  the  tongue  is  peculiarly  sensi- 
tive to  sweet  and  salt,  the  sides  to  sour,  and  the  base  to 
bitter.  It  is  a  curious  fact,  suggesting  the  existence  of 
special  receptors  for  the  different  kinds  of  sense  qualities, 


FIG.  36. — Surface  of  tongue  seen  from  above.  The  taste  buds  in 
which  the  gustatory  nerves  terminate  lie  mainly  in  the  walls 
of  1  and  2,  the  circumvallate  papilla;,  and  3,  the  fungiform 
papillae.  (After  Schiifer.) 

that  some  substances  produce  a  very  different  taste  upon 
different  parts  of  the  tongue.  At  the  tip,  saccharine  is  ex- 
tremely sweet,  at  the  base  it  tastes  bitter.  There  are  some 
indications  also  of  interrelations  of  an  intimate  kind  be- 
tween the  elementary  qualities.  Thus  there  are  drugs 
which  if  applied  to  the  surface  of  the  tongue  will  paralyze 
the  sensitivity  for  bitter  and  sweet  without  affecting  the 
other  tastes. 


104  AN  INTRODUCTION  TO  PSYCHOLOGY 

The  Gustatory  Sense  Organ. — In  order  that  a  substance 
may  be  tasted  at  all,  it  must  be  presented  in  liquid  form, 
and  no  solid,  if  taken  into  the  mouth,  can  be  tasted  unless  it 
is  soluble  by  the  saliva.  The  reason  for  this  seems  easy 
to  understand  when  it  is  remembered  that  the  receptors 
for  taste  stimuli  terminate  at  the  base  of  very  minute  cell 
structures  shown  in  Figs.  37,  38,  39,  which  lie  imbedded  in 
deep  crevices  in  the  walls  of  certain  papillae.  Direct  con- 
tact with  these  organs  is  thus  rendered  quite  impossible  ex- 
cept for  a  fluid.  As  has  been  pointed  out  in  the  preceding 
paragraph,  these  papillae,  whose  form  differs  considerably 
in  different  regions  of  the  tongue,  are  distributed  over 
the  sides,  tip,  and  base,  the  center  of  the  tongue  being 
substantially  destitute  of  them.  There  are  some  taste 
nerves  occasionally  found  in  the  cheeks  and  in  the  neigh- 
borhood of  the  palate.  Attention  has  already  been  called 
to  the  fact  that  what  we  commonly  designate  taste  is  in 
point  of  fact  a  fusion  of  smell,  taste,  temperature,  con- 
tact, and  movement.  The  tongue  is  very  richly  inner- 
^ated  with  receptors  for  contact,  pain,  temperature,  and 
movement. 

Olfactory  Sensations. — Sensations  of  smell  are,  as  we 
have  noticed,  intimately  connected  with  those  of  taste. 
This  connection  is  undoubtedly  very  ancient  and  repre- 
sents the  fundamental  importance  of  these  two  senses  as 
guardians  of  the  food  supplies  in  primitive  animal  con- 
ditions. Despite  this  intimate  connection,  smell  presents 
some  very  striking  contrasts  to  taste.  The  taste  qualities 
are  few  in  number  and  relatively  easy  to  isolate.  Smell, 
on  the  other  hand,  presents  an  almost  endless  complexity 
of  qualities,  which  can  at  best  be  grouped  together  in  cer- 
tain roughly  separable  classes.  The  taste  qualities  appear- 


SENSATION 


105 


to  be  connected  in  a  general  way  with  anatomically  dis- 
tinct regions.     Smell,  so  far  as  can  be  detected,  offers  no 


FIG.  37. — Vertical  section  of  circumvallate  papilla  of  a  calf.  A, 
the  papilla;  n,  the  gustatory  nerve  fibrils  terminating  in  and 
about  T,  the  taste  buds.  (After  Engelmann.) 


FIG.  38. — Vertical  section  through  a  taste  bud.  1,  gustatory  cells 
with  hair-like  terminals;  2,  supporting  cells.  (After  Cunning 
ham.) 


FIG.  39. — Diagram  of  the  cells  found  in  a  taste  bud.     a,  gustatory 
cells;   6,  supporting  cells.     (After  Cunningham.) 


106  AN  INTRODUCTION  TO  PSYCHOLOGY 

topographical  differentiation.  The  stimulus  to  taste,  must 
be  a  fluid.  The  stimulus  to  smell  must  be  a  gas,  or  at  all 
events,  finely  divided  particles  suspended  in  a  gas  such 
as  the  air. 

The  accompanying  table  contains  the  grouping  of  smell 
qualities  which  is  now  most  generally  employed  as  a  work- 
ing division.  It  is  a  modification  made  by  the  Dutch 
physiologist  Zwaardemaker  of  an  older  table  proposed  by 
the  botanist  Linnaeus. 

1 — Ethereal  smells,  including  fruit  odors. 

2 — Aromatic  smells,  e.g.,  camphor,  spice. 

3 — Fragrant  smells,  e.g.,  such  flowers  as  violets  and 
sweet  peas. 

4 — Ambrosiac  smells,  e.g.,  musk. 

5 — Alliaceous  smells,  e.g.,  garlic,  chlorine. 

6 — Empyreumatic  smells,  e.g.,  burning  tobacco,  burnt 
toast. 

7 — Hircine  smells,  e.g.,  cheese. 

8 — Virulent  smells,  e.g.,  opium. 

9 — Nauseous  smells,  e.g.,  decaying. animal  matter. 

The  difficulty  of  grouping  odors  or  of  reducing  them 
to  a  small  number  of  elementary  types  is  suggested  by  the 
fact  that  the  ordinary  method  of  designating  them  in- 
volves either  a  reference  to  the  names  of  the  objects  from 
which  they  come  (e.g.,  lemon  odor,  the  odor  of  roses,  etc.) 
or  characterizing  them  by  adjectives  borrowed  from  taste, 
as  when  we  speak  of  a  sweet  odor  or  a  sour  odor,  or  finally, 
grouping  them  as  agreeable  or  disagreeable. 

Olfactory  Sense  Organ. — Receptors  for  smell  terminate 
about  the  bases  of  little  hair-like  or  thread-like  cells  im- 
bedded in  the  mucous  membrane  of  the  upper  portion  of 
the  nasal  cavity.  (Fig.  40.)  Unlike  most  sensory  termi- 
nal organs  these  cells  are  apparently  themselves  true  nerv- 


SENSATION 


107 


ous  tissue.  The  general  location  of  this  olfactory  mem- 
brane may  be  seen  in  Figure  41.  This  figure  shows  graphi- 
cally how  in  gentle  breathing  the  air  currents  may  pass 


FIQ.  40. — Isolated  cells  from  olfactory  region  of  the  rabbit;  st,  sup- 
porting cells;  s,  short,  stiff  cilia,  or,  according  to  some  authori- 
ties, cones  of  mucus  resembling  cilia;  r,  r,  olfactory  cells.  (Mc- 
Kendrick  and  Snodgrass  after  Stohr.) 


FIG.  41. — Diagram  to  show  the  location  of  the  olfactory  end-organs 
and  the  course  of  the  air  currents  when  we  breathe.  0,  the 
olfactory  membrane  of  the  right  nostril  into  which  the  olfac- 
tory nerve  comes  down  through  the  bone  above.  The  black 
line,  numbered  1,  indicates  the  usual  course  of  the  air  in 
natural  breathing.  The  lighter  line,  numbered  2,  indicates  the 
course  of  the  air  when  we  inhale  strongly.  (Modified  from 
Zwaardemaker. ) 

up  through  the  nostrils  and  into  the  lungs  without  coming 
into  violent  contact  with  this  olfactory  region.  In  vigor- 
ous inhalation,  on  the  other  hand,  the  currents  of  air  are 


108     AN  INTRODUCTION  TO  PSYCHOLOGY 

drawn  up  sharply  against  the  membrane  and  we  secure 
vivid  and  distinct  sensations. 

As  in  the  case  of  taste,  but  to  a  less  degree,  there  is 
uncertainty  regarding  the  exact  cortical  terminations  of 
the  smell  nerves,  but  the  best-  modern  knowledge  is  em- 
bodied in  Figure  14,  opposite  page  36. 

Cutaneous  Sensations. — It  is  usual  to  speak  as  though 
the  skin  were  itself  a  sensitive  organ,  and  it  is  of  course 
true  that  we  feel  the  various  kinds  of  stimuli  which  come 
in  contact  with  it.  But  in  strictness,  the  skin  is  simply  a 
protective  covering  Avithin  whose  deeper  layers  the  real 
receptors  are  imbedded.  By  common  consent,  pressure, 
heat,  cold,  and  pain  are  mediated  by  skin  sensations. 
Ordinarily  two  or  more  of  these  are  aroused  together  by 
the  usual  forms  of  stimulation,  and  as  a  matter  of  fact 
there  are  generally  added  the  kinaesthetic  sensations  aris- 
ing from  muscular  movement.  Thus,  if  I  reach  out  my 
hand  and  grasp  the  book  lying  upon  the  table,  I  obtain 
sensations  of  contact,  of  temperature,  and  of  movement. 
If  I  burn  myself,  I  secure  simultaneously  sensations  of 
heat  and  pain. 

Contrary  to  the  usual  impression,  these  various  forms  of 
sensitivity  are  not  distributed  evenly  over  the  entire  bodily 
surface.  The  skin  presents  a  sort  of  mosaic,  with  points 
sensitive  to  one  kind  of  stimulation  interspersed  between 
points  sensitive  to  other  forms,  and  with  adjacent  points 
insensitive  to  all  kinds  of  stimuli.  Of  course  if  a  stimulus 
be  made  sufficiently  intense,  almost  any  region  will  re- 
spond. Nevertheless,  the  statement  just  made  is  essen- 
tially true.  (See  Fig.  42.) 

If  a  blunt  metal  point,  even  a  pencil  point,  be  cooled  and 
then  be  gently  passed  over  the  skin  of  the  back  of  the 


SENSATION  109 

hand,  there  will  be  spots  where  a  perfectly  distinct  flash 
of  cold  will  be  felt,  and  other  spots  on  which  either  con- 
tact alone  or  nothing  at  all  will  be  sensed.  A  similar  re- 
sult will  be  encountered  if  the  point  be  slightly  heated. 
Warmth  will  be  clearly  sensed  now  and  then,  but  will  be 
found  quite  lacking  at  other  points.  The  spots  sensitive 
to  pressure  are  more  numerous  than  those  sensitive  to 
warmth  and  cold  of  moderate  degree.  More  numerous 
than  either  are  the  spots  sensitive  to  painful  pressure, 


FIG.  42. — C,  cold  spots;  H,  hot  spots  from  an  area  on  the  back  of 
the  wrist.  Similar  spots  sensitive  to  pressure  and  to  pain 
respectively  have  been  charted.  (McKendrick  and  Snodgrass 
after  Goldscheider. ) 

like  that  of  a  needle.  There  are  some  regions,  like  the 
cornea  of  the  eye,  on  which  practically  only  pain  sensa- 
tions can  be  aroused.  Oddly  enough,  there  are  some  re- 
gions which  seem  quite  insensitive  to  pain  from  puncture. 
There  is  a  region  of  this  kind  on  the  inner  surface  of  the 
cheek.  The  sensitivity  differs  very  widely  on  various 
surfaces,  as  is  illustrated,  in  the  case  of  contact  or  pres- 
sure, by  the  tip  of  the  tongue,  the  tip  of  the  fingers,  and 
the  skin  just  above  the  elbow.  The  first  two  surfaces  are 
sensitive  to  differences  much  more  minute  than  those 
which  can  be  sensed  by  the  last  mentioned  region.  A 
simple  demonstration  may  be  made  by  lightly  touching 


110  AN  INTRODUCTION  TO  PSYCHOLOGY 

three  such  regions  with  a  pair  of  compass  points  set  a 
quarter  of  an  inch  apart.  A  similar  type  of  disparity 
characterizes  the  distribution  of  sensitivity  in  the  case  of 
the  other  skin  senses. 

Cutaneous  Sense  Organs. — Although  the  evidence  is 
not  as  yet  absolutely  conclusive,  there  is  strong  reason  to 
believe  that  the  receptors  for  the  different  kinds  of  sensa- 
tion mentioned  have  each  a  different  type  of  terminal 
organ.  Figure  43  exhibits  the  different  terminals  now 
plausibly  regarded  as  the  receiving  devices  for  the  differ- 
ent kinds  of  cutaneous  stimulations. 

The  cortical  receiving  stations  for  these  various  sensa- 
tions [with  the  possible  exception  of  pain,  which  is  perhaps 
represented  in  the  thalamus]  are  pretty  well  localized,  as 
shown  in  Figure  13,  in  the  region  posterior  to  the  fissure 
of  Rolando.  The  close  proximity  to  the  great  motor  zone 
(an  arrangement  suggestive  of  that  in  the  spinal  cord) 
must  not  be  overlooked,  and  will  not  be  thought  strange 
when  one  remembers  that  these  cutaneous  experiences  are 
probably  the  most  primitive  and  ancient  of  organic  life. 
Behavior  in  its  earliest  forms  was  in  considerable  measure 
simply  motor  adjustment  in  response  to  stimulations  of 
the  cutaneous  type. 

Kinaesthetic  Sensations. — We  have  frequently  had 
occasion  to  refer  to  sensations  of  movement.  Psycholo- 
gists generally  refer  to  these  as  kinaesthetic.  There  has 
been  little  successful  effort  to  analyze  them,  and  isolation 
is  particularly  difficult  because  they  occur  almost  without 
exception  in  conjunction  with  other  kinds  of  sensation. 
Various  illustrations  have  been  given  from  time  to  time 
of  these  combined  kinaesthetic  and  cutaneous  sensations. 
When  one  moves  the  hand,  there  is  almost  inevitably  a 


H.L. 


111 


A  X. 


FIG.  43. — A,  diagrammatic  cross  section  of  the  skin  showing  H.L., 
the  horny  layer  or  epidermis,  C.L.,  the  clear  layer,  G.L.,  the 
granular  layer,  M.L.,  the  mucous  layer,  P.L.,  the  papillary 
layer,  forming  the  outer  border  of  the  dermis;  N.E.,  nerve  end- 
ings, and  N.T.,  the  trunks  of  the  nerves.  B,  diagrammatic  cross 
section  of  the  skin  showing  a  hair  and  the  nerve  winding  about 
its  base;  H.,  the  hair;  H.L.,  horny  layer  of  the  epidermis;  N., 
nerve  trunk,  mediating  contact  sensations,  with  terminals,  T., 
about  the  base  of  the  hair.  C,  a  tactile  corpuscle  of  Meissner. 
AX.,  the  axonic  processes  wrapping  about  the  tissue  of  the  cor- 
puscle. A. C.,  naked  axis  cylinders.  D,  end-bulb  of  Krause, 
possibly  organ  of  sensations  of  cold.  AX.,  axones  entering  the 
bulb;  a.F.,  naked  axone  fibers;  T.C.,  so-called  touch  cells;  C.T., 
connective  tissue  of  the  skin.  E,  Pacinian  corpuscle,  probably 
concerned  in  contact  sensations;  AX.,  axone  entering  the  cor- 
puscle with  axis  cylinder  terminations  at  A.C. ;  C.T.,  connective 
tissue.  F,  Ruffini's  nerve  endings,  possibly  mediating  warmth 
sensations;  AX.,  axones;  T.O.,  terminal  organs;  G.T.,  con- 
nective tissue.  The  free  nerve  endings,  thought  to  mediate  pain 
sensations,  have  no  terminal  organ;  the  fibers  simply  thin  out 
to  a  point,  or  blunt  end,  and  stop.  (Modified  from  Cunningham, 
Retzius  and  Toldt.) 


112  AN  INTRODUCTION  TO  PSYCHOLOGY 

stretching  of  the  skin  so  as  to  produce  a  pressure  sensa- 
tion, which  tends  to  fuse  with  the  kinaesthetic  or  motor 
sensations,  thus  confusing,  or  at  least  obscuring,  somewhat 
the  characteristic  quality  of  the  motor  sensation  itself. 
It  is  the  general  view  today  that  these  kinaesthetic  sensa- 
tions are  due  to  the  stimulation  of  receptors  which  termi- 
nate in  the  muscle  surfaces,  or  in  the  insertions  of  ten- 
dons and  ligaments,  or  in  the  cartilaginous  surfaces  of 
joints.  Obviously,  under  ordinary  conditions  the  sensa- 
tions from  these  three  sources  would  tend  to  fuse  because 
they  practically  always  occur  together.  However  difficult 


FIG.  44. — Termination  of  sensory  nerve  in  a  tendon;  AX.,  axone; 
T.,  tendon;  T.O.,  terminal  organs.     (Modified  from  Morris.) 

of  isolation  and  analysis,  there  can  be  no  doubt  that  the 
sensations  of  this  group  play  an  extremely  important  part 
in  our  control  over  our  movements.  But  of  this  more  will 
be  said  at  a  later  point. 

Kinaesthetic  Sense  Organs. — Figure  44  illustrates  the 
type  of  terminal  organ  for  the  kinaesthetic  receptors.  The 
central  receiving  station  in  the  cortex  is  by  clinicians 
located  in  the  post-Rolandic  region  along  with  the  cuta- 
neous group  of  sensations. 

Organic  Sensations. — One  group  of  sensory  experi- 
ences remains  to  be  described.  These  are  designated  in  a 
general  way  organic  sensations.  To  this  group  strictly 
considered  should  be  assigned  the  kinaesthetic  sensations, 


SENSATION  113 

because  like  the  general  class  of  organic  sensations,  they 
are  caused  by  changes  occurring  inside  of  the  organism. 
It  is  convenient,  however,  to  distinguish  the  kinaesthetic 
group  from  the  others,  despite  this  common  property  of 
intra-organic  origin.  Ordinarily  sensations  of  touch, 
taste,  smell,  vision,  and  hearing  are  aroused  by  objects 
outside  the  body. 

Illustrations  of  these  organic  sensations  are  such  ex- 
periences as  arise  from  respiration  and  circulation.  The 
consciousness  of  feeling  choked  or  stifled  when  the  air  is 
close  is  an  instance  of  this  kind.  The  congestion  of  the 
head  when  one  is  ill  affords  another  example.  Hunger, 
thirst,  and  nausea,  are  still  other  instances.  Dizziness 
mentioned  in  connection  with  the  semicircular  canal  func- 
tions is  sometimes  included.  The  list  is  a  rather  long  one, 
and  need  not  be  given  in  detail  here.  The  reader  can 
doubtless  supply  many  other  illustrations. 

Receptors  for  Organic  Sensations. — The  receptors  for 
some  of  these  experiences  are  not  well  identified,  but  in 
general  they  no  doubt  belong  to  the  cutaneous  and  kin- 
aesthetic  type.  In  many  of  them  pain  is  represented,  and 
in  these  cases  presumably  the  receptor  is  similar  to  that 
already  described  for  painful  cutaneous  experiences.  The 
cortical  receiving  stations  are  also  problematical,  except 
in  so  far  as  the  sensations  are  identifiable  with  those  of 
kinaesthesis  and  the  cutaneous  sensation  group. 


CHAPTER  VII 
SENSE  PERCEPTION 

Sensation  and  Perception. — Throughout  the  previous 
chapter,  we  have  discussed  the  adjustive  sensory  processes 
with  regard  to  the  different  kinds  of  stimuli  which  arouse 
them,  the  different  qualities  of  sensation  which  are  called 
forth,  and  the  peculiar  structure  of  the  sense  organs  and 
nerves  upon  which  they  depend.  Psychologists  often 
speak  of  sensations  as  mental  elements,  because  they  are 
apparently  simple  qualities  which  resist  further  analysis, 
just  as  do  oxygen  and  the  other  chemical  elements.  Sen- 
sations are  supposed  to  combine  with  other  kinds  of  men- 
tal elements  called  simple  feelings,  to  be  mentioned  later, 
to  produce  mental  compounds  such  as  we  shall  deal  with 
from  this  point  on. 

We  now  pass  to  another  phase  of  these  sensory  activities, 
which  psychologists  commonly  call  perception,  defined  by 
James  as  "the  consciousness  of  particular  material  objects 
present  to  sense."  While  it  is  true  that  these  objects  seem 
in  a  certain  sense  to  be  simple  combinations  of  sense  quali- 
ties, nevertheless  what  we  see  when  we  open  our  eyes  is 
not  the  mere  color  quality  green,  but  green  leaves,  green 
grass,  and  other  green  objects.  Similarly,  when  we  hear 
sounds,  our  immediate  perception  is  of  a  street  car,  or  of 
a  locomotive  whistle,  or  of  a  class  bell.  Each  of  these 
Sounds  has  its  own  peculiar  sensation  quality  as  noise  or 
tone,  but  the  immediate  reaction  upon  hearing  any  one 
of  them  involves  our  identification  of  the  sound  in  the 

114 


SENSE  PERCEPTION  115 

manner  mentioned.  The  perception  conveys  meaning  to 
us.  It  involves  our  apprehension  of  some  at  least  of  the 
relations  sustained  by  the  object  to  other  objects,  e.g.,  its 
direction,  distance,  etc.  The  other  senses  will  all  illustrate 
the  same  thing.  We  perceive  a  book  in  part  by  the  im- 
pressions of  contact  and  temperature  which  come  from  the 
hand  as  we  grasp  it.  We  perceive  a  violet  by  its  odor, 
even  though  we  cannot  see  it.  However  meager  the  sen- 
sory data  with  which  we  are  supplied,  in  each  case  we 
tend  to  perceive  an  object  with  a  more  or  less  definite 
fringe  of  relations.  It  is,  then,  to  an  analysis  of  certain 
features  of  these  perceptual  operations  that  we  must  next 
proceed. 

As  contrasted  with  sensation,  in  the  psychologist 's  mean- 
ing of  the  term  as  the  consciousness  of  sensory  quality, 
perception  is  relatively  more  real  and  more  concrete.  To 
get  at  a  sensation  of  color  involves  our  abstracting  it  from 
the  general  complex  in  which  it  is  imbedded.  The  color 
of  a  ribbon  may  thus  be  considered  apart  from  the  special 
texture  of  the  fabric  in  which  it  appears  and  apart  from 
the  other  colors  surrounding  it.  We  can  only  direct  atten- 
tion to  the  color  itself  by  thus  disregarding  all  the  other 
accompanying  circumstances.  In  perception  we  have  a 
mental  state  in  which  we  apprehend  a  group  of  sensory 
qualities  as  an  object,  in  this  case  the  ribbon.  To  be  sure, 
as  was  pointed  out  when  discussing  attention,,  the  very 
process  by  which  we  perceive  one  object  involves  our  dis- 
regarding more  or  less  all  other  objects.  Even  here,  then, 
there  is  a  certain  sort  of  abstraction  and  isolation.  But 
from  the  common-sense  point  of  view  sense  perception  gives 
us  the  real  objects  of  daily  life,  the  tables  and  chairs,  cats 
and  dogs,  sticks  and  stones  of  every-day  experience. 


116     AN  INTRODUCTION  TO  PSYCHOLOGY 

Organization  of  Sensations  in  Perception. — As  an  ad- 
justive  process,  perception  represents  very  distinctly  an 
organization  of  sensations  into  units  such  that  we  can  make 
practical  motor  responses  to  them.  An  apple,  as  a  mere 
matter  of  sensation,  appeals  to  touch,  sight,  smell,  and 
taste,  to  mention  no  other  possibilities.  As  a  perception 
all  these  qualities  are  centered  in  the  object  to  which  by 
extending  the  hand  we  can  make  an  effective  and  satis- 
factory response.  As  compared  with  animals,  human 
beings  undoubtedly  make  far  less  use  of  smell,  and  prob- 
ably much  less  of  taste,  as  guides  to  their  larger  bodily 
reactions.  Vision,  hearing,  and  contact  afford  the  pre- 
dominant foci  of  human  perceptions. 

Part  Played  in  Perception  by  Previous  Experience. — 
"We  saw  in  an  earlier  chapter  that  constant  modification  is 
taking  place  in  our  reactions  by  virtue  of  our  ability  to 
carry  over  from  one  moment  to  the  next  that  which  we 
have  learned.  This  fact  is  perfectly  obvious  in  all  the 
instances  of  gross  general  behavior,  such  as  the  learning  of 
a  new  motor  habit  like  skating.  The  same  principle 
applies,  however,  to  perception  as  to  all  other  conscious 
processes.  To  the  plain  man  it  seems  obvious  that  what 
he  perceives  when  he  looks  across  the  room  and  sees  a 
square-topped  table  is  simply  that  which  is  before  his  eyes. 
As  a  matter  of  fact  what  he  perceives  is  in  no  sense  merely 
that  which  is  physically  present  to  his  retinae,  but  a  much 
more  complex  object  and  one  which  in  certain  particulars 
differs  essentially  from  that  presented  to  his  eyes.  To 
take  but  a  single  feature  of  the  situation :  if  he  be  standing 
across  the  room,  as  assumed  in  the  illustration,  the  table 
top  which  he  sees  as  square, — that  is,  with  four  right 
angles  and  equal  sides — is  projected  on  his  retinae  as  a 


SENSE  PERCEPTION  117 

figure  with  two  obtuse  and  two  acute  angles.  If  he  really 
saw  simply  what  is  optically  before  him,  he  would  per- 
ceive a  figure  of  the  rhomboid  type,  and  not  a  square  at 
all.  The  truth  of  this  statement  becomes  apparent  the  mo- 
ment one  tries  to  draw  a  table  as  seen  from  such  a  position. 
If  one  uses  actual  right  angles  in  the  sketch,  the  drawing 
will  be  a  failure.  Moreover,  when  one  looks  at  a  polished 
wood  or  metal  surface,  as  in  a  case  like  that  of  our  illus- 
tration, one  gets  something  of  the  feelings  of  smoothness, 
coolness,  and  hardness,  all  of  which  are  tactual  qualities 
that  somehow  fuse  with  the  visual  impression.  A  percep- 
tion may  thus  involve  sensory  qualities  belonging  to  other 
sense  organs  than  that  directly  stimulated  at  the  moment. 
It  is  sometimes  said  that  we  see  what  we  expect  to  see, 
or  what  we  are  accustomed  to  see,  and  this  is  true  in  a 
much  more  intimate  and  thorough-going  way  than  is  ordi- 
narily appreciated.  We  tend  to  interpret  every  sensory 
stimulus,  like  the  table  top,  in  terms  of  our  previous  ex- 
perience of  similar  objects,  and  for  the  most  part  we 
assume  that  that  sort  of  perception  which  is  most  con- 
sistent with  all  our  experiences  of  the  object  in  question 
presents  its  'true'  or  'real'  form.  Language  is  a  par- 
ticularly striking  instance  of  the  effects  of  experience  upon 
our  perceiving.  The  words  of  a  strange  language  may 
strike  upon  the  ear  in  absolutely  the  same  fashion  in  which 
they  do  at  a  later  period  after  the  language  has  been  mas- 
tered. The  sensations  elicited  in  the  two  cases  may  really 
be  to  all  intents  and  purposes  identical;  but  the  percep- 
tions are  radically  different.  In  the  first  instance  we  hear 
simply  a  melange  of  meaningless  sound;  in  the  second, 
experience  furnishes  a  whole  host  of  interpretative  mean- 
ings which  are  entirely  missing  ir.  the  first  case.  What 


118  AN  INTRODUCTION  TO  PSYCHOLOGY 

we  perceive  at  any  given  moment  is  quite  as  much  de- 
termined by  our  momentary  interests,  by  our  past  ex- 
perience and  the  modifications  which  it  has  impressed  upon 
the  nervous  system,  as  by  the  particular  object  physically 
present  to  our  senses. 

Perception  and  Illusion. — Certain  illusions,  which  are 
simply  erroneous  perceptions,  furnish  additional  evidence 
of  the  dependence  of  perception  upon  preceding  experi- 
ence.1 The  figure  (45)  sketched  on  this  page,  like  that  on 


FIG.  45.— (After  Gordon.) 

1  Illusions  may  be  roughly  grouped  as  arising    ( 1 )    from  habits, 

(2)  from  expectancy,  and  (3)  from  sense  organ  structure.     (1)   We 
perceive   a   rumbling  noise   as   a   distant   train  because   that    is   a 
common  source  of  such  a  sound.     In  the  present  case  it  may  be 
thunder.     (2)   We  waken  in  the  night,  fear  burglars  and  distinctly 
hear  footsteps — which  are  as  a  matter  of  fact  simply  the  sounds 
of  the  creaking  of  boards  caused  by  wind  or  change  of  temperature. 

(3)  Figure  47,  page  127,  exhibits  illusions  which  belong  at  least  in 
part  to  this  group. 

Like  illusions,  hallucinations  are  false  perceptions,  but  in  this  case 
apparently  no  external  physical  stimulus  is  present.  They  may  be 
due  to  derangements  in  the  sense  organs  or  in  the  cerebral  cortex. 
They  are  common  in  certain  forms  of  insanity  and  may  involve  any 
of  the  senses. 


SENSE  PERCEPTION  119 

page  60,  may  be  seen  in  at  least  three  different  ways.  The 
figure  may  be  perceived  as  a  pile  of  cubes  with  black  sur- 
faces uppermost,  or  as  a  cornice  which  one  is  looking  at 
from  below,  or  finally — though  this  is  difficult  to  observe 
for  more  than  an  instant — as  a  flat  mosaic  of  black,  white, 
and  gray  diamonds.  The  reader  will  note  that  in  each 
case  the  retinal  stimulus  is  absolutely  identical,  and  yet 
three  quite  distinct  objects  are  perceived.  Clearly  this 
result  can  only  be  explained  by  the  fact  that  one 's  previous 
experience  affords  the  three  different  contexts  for  one  and 
the  same  set  of  lines.  Which  particular  group  shall  be 
brought  into  action  at  any  one  moment  is  evidently  more 
or  less  accidental.  Typographical  errors  are  overlooked 
by  the  ordinary  reader  unless  they  are  very  serious,  be- 
cause he  sees  what  he  is  in  the  habit  of  seeing,  and  not 
what  is  really  before  him.  Thus  the  error  in  the  phrase 
'Pacific  Ocaan'  will  by  many  readers  be  entirely  unnoticed. 
The  extent  to  which  these  perceptual  reactions  acquire 
meaning  from  previous  experience  should  make  it  clear 
that  the  organization  of  sensation  which  is  represented,  is 
in  large  measure  embodied  in  the  cortical  neurones.  To 
perceive  a  couple  of  dozen  lines  as  a  pyramid  of  cubes  in- 
volves the  arousal  in  an  organized  and  systematic  fashion 
of  large  groups  of  cerebral  neurones,  and  it  is  evident  that 
the  type  of  motor  reaction  appropriate  to  dealing  with  the 
pyramid  experience  would  be  decidedly  different  from  that 
required  by  the  cornice  experience.  The  organization, 
therefore,  of  our  sensations  exhibited  in  perception  is  re- 
flected in  a  corresponding  organization  of  motor  response. 
The  two  things  go  together.  Both  are  subject  to  the  gen- 
eral principle  of  habit,  which  we  discussed  rather  fully  in 
Chapter  IV. 


120  AN  INTRODUCTION  TO  PSYCHOLOGY 

Perception  of  Time  and  Space. — Perception  not  only 
gives  us  our  contact  with  the  physical  world  of  objects, 
but  it  is  also  the  channel  through  which  we  gain  our 
knowledge  of  space  and  time.  It  is  sometimes  said  that 
all  our  perceptions  come  to  us  imbedded  in  time  and 
most  of  them  in  space.  Our  common  phrases  sug- 
gest that  we  perceive  both  time  and  space  just  as  we 
perceive  objects.  Philosophy  has  from  the  earliest  times 
busied  itself  with  the  attempt  to  understand  the  ultimate 
nature  of  these  two  forms  of  experience.  We  must  try  to 
steer  clear  of  the  more  metaphysical  aspects  of  the  prob- 
lem, but  we  can  hardly  forego  some  slight  study  of  the 
psychology  of  the  processes.  Our  adjustments  to  our  sur- 
roundings occur  in  a  medium  of  both  time  and  space,  and 
the  effectiveness  of  our  reactions  is  largely  conditioned  by 
our  ability  to  make  intelligent  allowance  for  these 
factors. 

Space  Perception  and  the  Several  Senses. — There  has 
been  some  controversy  among  psychologists  as  to  whether 
all  of  our  senses  are  capable  of  mediating  experiences  of 
space.  Vision,  touch,  and  the  kinaesthetic  sensations  have 
generally  been  accepted  as  self-evident  sources  of  space 
perception.  The  other  senses,  and  particularly  hearing, 
have  been  the  chief  centers  of  discussion.  William  James, 
for  example,  was  wont  to  maintain  that  all  sensory  experi- 
ence is  'voluminous.'  He  held  that  certain  sounds  are 
massive,  and  others  thin  and  fragile.  Similarly,  he  main- 
tained that  some  odors  are  big  and  expansive  as  compared 
with  others.  Taste  is  hardly  a  profitable  source  of  discus- 
sion, because  it  is  compromised  by  its  connection  with  con- 
tact and  temperature.  The  precise  meaning  of  the  contro- 
versy can  perhaps  be  better  understood  after  we  have 


SENSE  PERCEPTION  121 

analyzed  some  of  the  conspicuous  features  in  the  percep- 
tion of  space. 

In  animal  life,  and  particularly  in  its  lower  stages,  the 
adjustment  to  space  relations  hinges  very  largely  upon  the 
factor  of  direction.  The  creature  needs  to  go  in  the  gen- 
eral direction  of  its  food  supply  and  needs  to  retreat  from 
locations  where  its  enemies  are  found.  Another  important 
capacity,  from  which  the  sense  of  direction  has  perhaps 
developed,  is  the  ability  to  localize  stimulations  upon  the 
bodily  surfaces.  Behavior  of  this  type,  as  when  a  frog 
lifts  one  of  its  legs  to  wipe  off  an  injurious  substance  from 
its  body,  obviously  involves  a  form  of  spacial  adjustment. 
The  perception  of  distance  and  the  perception  of  shape 
and  size  are  presumably  somewhat  later  acquirements, 
although  many  of  the  lower  animals  seem  to  have  a 
relatively  accurate  ability  to  estimate  distances  near  at 
hand. 

If  we  consider  first  the  capacity  to  detect  direction,  i», 
is  fairly  clear  that  vision,  touch,  movement,  hearing,  and 
smell  may  all  serve  us  with  varying  degrees  of  accuracy, 
and  that  possibly  taste  would  also  be  found  in  this  group 
if  it  could  be  separated  from  touch.  If  we  are  to  make 
the  detection  of  direction  our  criterion,  we  can  hardly 
deny  spacial  character  to  any  of  our  sensations,  at  least 
not  if  we  permit  the  cooperation  of  movement.  But  when 
we  turn  to  the  other  factors  mentioned  we  find  ourselves 
led  to  quite  a  different  conclusion. 

Visual  objects  clearly  have  shape  and  size,  and  these 
qualities  we  perceive  quite  as  truly  as  we  perceive  the 
objects  possessing  them.  Indeed,  in  a  sense  they  are  one 
and  the  same.  But  who  would  ever  think  of  the  possi- 
bility of  perceiving  a  square  sound,  or  a  round  odor? 


122  AN  INTRODUCTION  TO  PSYCHOLOGY 

Certain  psychologists  maintain,  to  be  sure,  as  we  have 
already  implied,  that  some  sounds  are  larger  than  others, 
some  odors  more  voluminous.  Thus  the  sound  of  a  bass 
drum  is  alleged  to  be  bigger  than  the  shrill  whistle  of  a 
fife,  and  the  odors  of  garlic,  onions,  and  illuminating  gas 
are  thought  of  as  more  pervasive,  more  space-occupying 
than  the  odors  of  violets,  sandalwood,  and  lemons. 

There  are  certain  obvious  sources  of  possible  confusion 
in  such  supposed  evidence  as  has  just  been  advanced.  In 
the  case  of  the  bass  drum,  there  is  to  be  mentioned  the  in- 
tensity of  the  sound,  which  has  as  one  of  its  results  a 
more  or  less  general  bodily  jarring  which  naturally  con- 
veys an  impression  of  bigness.  Associated  with  this  is  often 
our  knowledge  of  the  majestic  proportions  of  the  instru- 
ment from  which  the  noise  proceeds.  One  or  both  of  these 
factors  are  likely  to  affect  our  impressions  of  the  volume 
of  the  sound.  But  even  admitting  the  strong  suggestion  of 
spacial  character  which  the  sound  brings  us,  no  one  would 
undertake  to  describe  the  shape  of  such  sounds,  or  to 
estimate  their  exact  size  with  reference  to  other  sounds. 
One  sound  may  be  louder  than  another,  that  is,  more  in- 
tense, and  we  often  venture  to  estimate  the  relative  in- 
tensity of  such  sounds,  but  measures  of  their  size  and 
shape  one  never  undertakes. 

Exactly  the  same  kind  of  consideration  may  be  urged 
about  odors.  Undoubtedly  we'  find  them  suggestive  of 
spacial  qualities,  and  we  certainly  localize  them  more  or 
less  accurately.  But  the  complete  list  of  spacial  character- 
istics, including  size  and  shape,  which  are  so  clearly  fea- 
tures of  the  visual-touch-movement  space  experiences,  are 
certainly  lacking.  We  can  hardly,  then,  deny  to  them 
whatever  of  space  character  belongs  to  the  ability  to  dis- 


SENSE  PERCEPTION  123 

cern  direction,  but  we  can  certainly  not  attribute  to  them 
the  full  quota  of  space  properties. 

We  must  now  turn  back  to  examine  in  more  detail  the 
important  peculiarities  of  the  several  senses  as  media  of 
space  perception. 

Space  Perception  from  Smell. — Apart  from  its  vague 
suggestion  of  space  relations,  to  which  we  have  already  re- 
ferred, human  beings  secure  through  smell  only  very  crude 
impressions  of  direction.  If  we  wish  to  identify  the  direc- 
tion from  which  an  odor  is  coming,  it  is  almost  essential 
that  we  should  turn  the  head  in  this  direction  and  that 
until  we  have  determined  at  what  point  the  odor  is  most 
intense.  Whether  the  human  sense  of  smell  has  suffered 
atrophy  or  not  in  the  evolution  from  our  animal  ancestry, 
there  can  be  no  question  that  at  the  present  time  many 
animals  excel  us  hopelessly  in  the  accuracy  and  delicacy 
with  which  they  make  use  of  this  sense. 

Auditory  Space  Perception. — In  even  greater  degree, 
perhaps,  than  smell,  hearing  conveys  suggestions  of  many 
kinds  of  space  relations,  but  its  only  unequivocal  spacial 
function  is  the  determination  of  direction,  in  which  it  is 
distinctly  superior.  Within  certain  limits,  to  be  described, 
we  can  localize  sound  promptly  and  with  a  measure  of 
accuracy.  This  capacity  is  dependent  in  largest  part  on 
the  fact  that  we  have  two  ears  and  that  sounds  often 
come  to  us  in  such  a  way  as  to  stimulate  one  ear  more 
strongly  than  the  other.  This  is  obviously  true  of  all 
sounds  except  those  in  the  median  vertical  plane  of  the 
body  at  right  angles  to  the  line  joining  the  ears.  In  this 
plane  localization  is  extremely  inaccurate,  and  with  closed 
eyes  an  inexperienced  person  is  generally  quite  unable  to 
determine  whether  sounds  are  in  front  of,  or  behind,  the 


124 

head,  and  whether  they  are  high  up  or  low  down.  On 
the  other  hand,  sounds  originating  from  points  on  either 
side  of  this  plane  and  a  few  degrees  outside  of  it  are 
localized  instantly  and  with  great  confidence  as  to  the 
side  from  which  they  come ;  but  it  is  often  extremely  diffi- 
cult, without  the  assistance  of  vision,  or  without  movement 
of  the  head,  to  determine  whether  the  sound  is  somewhat 
in  front  of,  or  somewhat  behind,  the  line  joining  the 
ears. 

The  ease  or  difficulty  of  these  localizations  is  related  in 
part  to  the  character  of  the  sound  itself.  While  with  nor- 
mal individuals  there  is  never  any  difficulty  in  determin- 
ing from  which  side  a  sound  comes,  the  accuracy  of  the 
localization  as  regards  the  more  exact  position  is  far 
higher  with  noises  and  with  complex  tones  than  it  is  with 
simple  tones,  like  those  of  a  tuning  fork.  The  reason  for 
this  seems  to  be  that  the  overtones  of  noises  and  complex 
tones  are  so  affected  by  the  conch  of  the  ear  (some  being 
reinforced  and  some  dampened)  that  they  sound  differ- 
ently when  heard,  for  example,  at  a  point  somewhat  to 
the  left  and  in  front  of  the  face  and  when  heard  at  the 
left  but  toward  the  back  of  the  head.  Pure  tones,  being 
devoid  of  overtones,  are  not  thus  affected  and  therefore 
cannot  be  so  distinguished. 

In  practical  daily  life  we  are  able  to  estimate  the  dis- 
tance of  sounds  as  well  as  their  direction.  But  this  is  a 
faculty  which  is  very  unreliable  except  where  we  are 
familiar  with  the  sounds.  It  is  easy  enough  to  demonstrate 
that  with  the  eyes  closed  a  very  faint  sound  near  at  hand 
is  readily  confused  with  a  stronger  sound  further  away. 
Gently  sounding  tuning  forks  afford  the  most  convincing 
and  ready  proof  of  this  fact,  and  everybody  must  at  one 


SENSE  PERCEPTION-  125 

time  or  another  have  been  deceived  into  thinking  some 
faint  sound,  like  the  hissing  of  a  steam  radiator,  was  some 
distant  object,  in  this  case  perhaps  a  locomotive  blowing 
off  steam. 

Visual  Space  Perception. — In  point  of  range  and  deli- 
cacy of  spacial  perception  vision  easily  surpasses  any  of 
the  other  senses.  Its  range  in  distance  is  limited  only  by 
the  clearness  of  the  air  and  the  curvature  of  the  earth's 
surface.  It  detects  direction  instantly  and  accurately.  It 
enables  us  to  judge  with  great  precision  both  the  size  and 
shape  of  objects.  Thanks  to  the  binocular  nature  of  the 
sense  organ  we  get  a  direct  visual  experience  of  solidity, 
for  the  right  eye  sees  a  part  of  a  solid  object,  such  as  a 
pencil,  hidden  from  the  left  eye,  and  vice  versa.  The 
stereoscope  takes  advantage  of  this  fact  and  presents  photo- 
graphs which  exaggerate  this  feeling  of  depth  because  they 
are  taken  from  positions  further  to  the  right  and  left  re- 
spectively, than  those  normally  occupied  by  the  eyes  in 
looking  at  the  object. 

Although  most  of  our  judgments  of  visual  distance  are 
probably  influenced  by  experiential  factors  involving 
touch  and  movement,  the  eye  has  its  own  mechanism  for 
detecting  distance  changes,  to-wit,  alterations  in  the  mus- 
cular sensations  of  convergence  and  accommodation,  the 
former  depending  on  the  movements  of  the  external  mus- 
cles of  the  eye,  the  latter  on  the  ciliary  muscles  controlling 
the  lens.  The  size  and  distinctness  of  the  retinal  image 
also  gives  us  a  clue.  The  nearer  the  object  the  larger 
and  more  distinct  the  image.  If  we  know  the  size  of  the 
object,  we  can  estimate  the  distance;  and  conversely  if 
we  know  the  distance,  we  can  estimate  the  size  of  the 
object.  The  accuracy  of  such  estimates  of  course  varies 


126  AN  INTRODUCTION  TO  PSYCHOLOGY 

with  different  conditions.  Figure  46  illustrates  the  essen- 
tial relations  involved. 

We  also  learn  very  readily  to  judge  of  distance  relations 
by  light  and  shade  effects,  as  seen  in  the  contours  of  a  dis- 
tant roof.  Color  aids  us,  too,  and  aerial  perspective,  but 
only  when  we  have  learned  how  to  interpret  what  we  see. 
Distant  mountains,  for  example,  tend  to  take  on  bluish  and 
purplish  hues. 

Accurate  and  sensitive  as  vision  is,  it  is  nevertheless 


FIG.  46. — The  retinal  image  db  of  the  object  AB  evidently  is  of 
the  same  size  as  the  images  of  the  object  XY  much  farther  dis- 
tant and  the  object  LM  much  nearer  at  hand.  Unless  our 
knowledge  about  the  objects  enabled  us  to  make  allowance  for 
the  different  distances,  we  should  be  at  a  loss  to  know  their 
relative  size. 


subject  to  certain  striking  illusions  of  which  a  few  are 
shown  in  Figure  47,  with  no  attempt  to  explain  them. 

Space  Perception  from  Touch. — Touch  has  figured 
historically  as  the  fundamental  spacial  sense,  from  which 
all  the  others  are  in  a  way  derivatives.  We  have,  at  an 
earlier  pointy,  indicated  the  limits  within  which  this  state- 
ment is  true.  It  is  a  fact  that  while  under  ordinary  con- 
ditions vision  is  much  more  important  to  us  as  a  space 
purveying  sense,  nevertheless  in  cases  of  doubt  or  hesita- 
tion we  are  wont  to  accept  the  verdict  of  touch  as  the 
final  index  of  reality.  In  the  spacial  world  of  daily  life, 
however,  touch  is  simply  one  of  a  group  of  factors  which 


SENSE  PERCEPTION 


127 


/ 


^^? 


a 


a 


Fxo.  47. — The  horizontal  lines  in  A  are  of  equal  length,  although 
they  do  not  so  appear.  •  In  B  the  line  which  really  continues  a 
does  not  appear  to  do  so.  In  C  the  lower  figure  appears  clearly 
larger,  although  upper  and  lower  are  exactly  equal  in  area. 
In  D  the  parallel  lines  no  longer  appear  parallel.  In  E  the 
filled  spaces,  06,  appear  longer  than  the  equal  unfilled  spaces, 


128  AN  INTRODUCTION  TO  PSYCHOLOGY 

cooperate  with  one  another  to  give  us  our  actual  space 
world. 

In  the  first  instance,  touch  is  the  great  medium  through 
which  we  locate  stimuli  upon  our  bodily  surfaces.  It  will 
be  remembered  that  in  our  study  of  the  nervous  system 
we  found  it  so  arranged  that  the  receptors  from  the  skin 
surfaces  are  immediately  connected  in  the  central  system 
with  effectors  leading  out  into  muscles  controlling  these 
same  cutaneous  regions.  This  mechanism  is  obviously  de- 
signed to  enable  the  immediate  movement  of  a  stimulated 
region.  Genetically  there  can  be  no  doubt  that  the  pro- 
tective value  of  these  localizing  movements  has  been  very 
great. 

In  the  human  being  the  power  of  localization  on  the 
skin  varies  enormously  on  the  different  body  surfaces,  as 
was  suggested  in  the  preceding  chapter.  On  the  finger 
tips  and  the  palms  of  the  hand,  it  is  relatively  delicate, 
on  the  back  of  the  arms,  on  the  back  of  the  trunk,  and  on 
large  parts  of  the  legs  the  localization  is  crude  and  coarse. 
The  truth  of  these  statements  can  be  promptly  demon- 
strated by  allowing  another  person,  while  one's  eyes 
are  closed,  to  touch  lightly  with  a  pen  point  the  skin 
of  the  hand  and  the  back  of  the  forearm,  and  immediately 
thereafter  trying  with  a  similar  point  to  touch  one's  own 
skin  on  the  spots  previously  stimulated.  The  differences 
in  the  sensitiveness  of  the  surfaces  for  localization  will  be 
immediately  seen  to  be  very  great.  Another  interesting 
method  of  demonstrating  the  same  kind  of  thing  is  to  take 
a  pair  of  dividers,  separate  the  ppints  by  about  an  inch, 
touch  the  skin  of  the  cheek  with  the  two  points  just  in 
front  of  the  ear  and  then  draw  them  lightly  across  the 
face,  passing  with  one  point  just  above  and  the  other  just 


SENSE  PERCEPTION  129 

below  the  lips,  and  so  across  to  the  other  ear.  With  the 
points  a  little  closer  together  a  similar  experiment  may  be 
made  by  starting  with  the  points  on  the  tip  of  the  inner 
side  of  the  middle  finger,  thence  passing  up  over  the  finger 
across  the  palm  and  up  the  wrist  and  forearm  to  the 
shoulder.  In  both  experiments  the  points  will  be  felt  to 
be  spreading  and  coming  together  again  in  the  most  amaz- 
ing fashion.  This  is  because  the  sensitivity  of  the  regions 
explored  is  so  very  different,  a  fact  explicable  by  the  varia- 
tions in  the  richness  of  the  nerve  supply  in  the  areas 
traversed. 

In  addition  to  the  power  of  localization,  touch  possesses 
also  the  capacity  to  report  size  and  shape  with  reasonable 
accuracy.  It  arises  from  the  only  sense  organ  which  is 
itself  capable  of  conforming  to  a  three-dimensioned  object, 
e.g.,  when  we  grasp  a  golf  ball  in  the  hand,  and  it  has 
been  a  favorite  doctrine  at  one  time  and  another  that  we 
are  indebted  to  touch  alone  for  all  our  original  knowledge 
of  the  third  dimension,  or  distance.  However  it  may  fare 
with  this  particular  view,  no  one  is  disposed  to  question 
that  touch,  in  connection  with  movement  at  least,  does  give 
us  tri-dimensional  experiences. 

In  speaking  of  touch  in  this  way  it  is  generally  under- 
stood that  temperature  sensations  are  included.  As  a 
matter  of  fact,  practically  all  touch  experiences  have  some 
temperature  elements  attached  to  them,  and  in  some  cases 
this  substantially  affects  our  spacial  judgments.  For 
instance,  an  object  which  is  distinctly  hot  or  cold,  if 
pressed  upon  the  skin,  is  likely  to  be  judged  larger — 
and  heavier — than  the  same  object  if  thermally  indifferent. 
A  coin  may  serve  to  make  such  an  experiment  with.  Of 
course  it  frequently  happens  that  in  passing  from  a 


130  AN  INTRODUCTION  TO  PSYCHOLOGY 

warmer  to  a  colder  temperature,  as  when  one  goes  out  of 
doors  on  a  cold  day,  one  encounters  a  considerable  mass  of 
temperature  sensations  without  any  accompanying  touch 
experience.  In  these  cases  we  get  a  general  massive  tem- 
perature impression,  which  has  a  certain  vague  spacial 
character,  but  unless  it  be  combined  with  contact,  we 
seldom  think  of  it  as  possessing  shape  or  definite  size. 
Practically,  therefore,  we  make  little  or  no  use  of  thermal 
sensations  as  sources  of  space  experience  save  for  purposes 
of  very  general  orientation,  as  when  we  approach  or  move 
away  from  a  source  of  heat.  Cutaneous  pain  is  even  less 
significant  as  a  factor  in  space  perception. 

Motor  Sensations  in  Space  Perception. — Although 
movement  gives  us  through  the  sensations  which  it  immedi- 
ately evokes  only  vague,  crude  space  perceptions,  it  is  of 
the  utmost  importance  in  the  exact  use  of  practically  all 
the  other  spacial  senses.  In  the  first  place,  it  is  to  be 
remarked  that  kinaesthetic  sensations  are,  as  a  matter  of 
fact,  all  but  invariably  connected  with  other  sensations, 
and  particularly  with  the  cutaneous  group.  If  one  moves 
the  hand,  thus  occasioning  sensations  of  movement  from 
the  muscles  and  joints,  one  simultaneously  produces 
through  changes  in  skin  tension  a  group  of  touch  impres- 
sions. If  the  eye  be  moved,  there  is  again  a  group  of 
vague,  but  real  contact  sensations,  to  say  nothing  of  the 
retinal  changes  which  also  set  up  visual  sensations.  The 
anatomical  conditions  which  bring  about  this  conjoint 
excitation  of  kinaesthetic  with  other  sense  stimulations  are 
no  doubt  responsible  for  the  widely  recognized  fact  that 
movement  is  largely  employed  as  a  measure  of  the  other 
forms  of  spacial  sensation. 

In  those  types  of  experience  in  which  we  gain  control 


SENSE  PERCEPTION  131 

over  the  larger  space  relations  it  is  fairly  clear  that  move- 
ment sensations  play  some  such  part  as  that  just  intimated. 
For  example,  the  child  learns  the  real  distance  from  side 
to  side  of  a  room  only  by  creeping  or  walking.  It  is  in 
terms  of  the  effort  required  to  pass  from  one  point  to 
another,  that  one  learns  to  give  some  precise  content  to 
such  a  distance  as  the  mile.  In  one  sense  the  basis  of  all 
these  spacial  experiences  is  resident  in  the  contact  sensa- 
tions coming  from  the  soles  of  the  feet,  and  in  the  visual 
sensations  arising  from  the  momentarily  changing  point  of 
view.  But  the  sensations  which  come  from  joint  and 
muscle  are  quite  as  fundamental.  These  serve  to  punctu- 
ate, as  it  were,  with  each  rhythmic  movement  of  the  limbs, 
the  amount  of  the  other  sensory  data,  visual,  tactual  or 
what  not,  which  is  ultimately  translated  into  terms  of  dis- 
tance. Upon  the  product  of  these  several  factors  is  finally 
placed  the  conventional  label  in  terms  of  feet  or  yards  or 
miles. 

It  is  interesting  to  remark  in  connection  with  this  gen- 
eral commentary  on  the  organization  into  a  working  sys- 
tem of  our  space  perceptions  from  different  senses,  that 
there  always  remain  outstanding  certain  unreconciled  dis- 
parities. For  example,  the  cavity  in  the  tooth  which  feels 
so  huge  to  the  tongue  is  a  poor  thing  when  explored  by 
the  finger  tip  or  examined  by  the  eye.  Many  other 
similar  instances  could  be  mentioned.  Doubtless  they  rep- 
resent discrepancies  in  the  reports  of  the  several  senses 
which  have  too  little  practical  importance  to  occasion  their 
reconciliation. 

Organic  Sensations  and  Space. — The  organic  sensa- 
tions, other  than  those  of  the  kinaesthetic  group  can,  in 
the  nature  of  the  case,  give  us  oniy  space  perceptions  of  our 


132  AN  INTRODUCTION  TO  PSYCHOLOGY 

own  inner  bodily  conditions.  For  the  most  part  the  spacial 
impressions  thus  aroused,  e.g.,  visceral  sensations  from  the 
abdomen,  are  extremely  vague  in  character.  Certainly 
they  play  no  important  part  in  our  general  spacial  orienta- 
tion. The  reflex  functions  of  the  semicircular  canals 
while  highly  significant  for  the  preservation  of  balance, 
and  so  for  space  adjustments,  give  us  ordinarily  little  or  no 
direct  conscious  report,  so  we  need  not  consider  them  in 
this  connection. 

The  Perception  of  Time. — We  have  seen  that  although 
taken  literally  every  one  of  our  senses  may  contribute  to 
our  appreciation  of  space  relations,  it  is  to  a  selected  few, 
particularly  vision,  touch,  and  movement,  that  we  are 
indebted  for  our  more  accurate  estimates  of  distance,  direc- 
tion, shape,  and  size.  In  the  same  way  all  the  senses  may 
contribute  to  our  appreciation  of  the  passage  of  time. 
But  it  is  especially  to  hearing  and  movement  that  we  owe 
our  more  accurate  estimates,  at  least  for  the  briefer  inter- 
vals for  which  we  have  something  fairly  to  be  called 
direct  perception.  The  longer  intervals  of  time  are  in 
general  judged  indirectly  by  means  of  symbols  of  one  kind 
or  another.  Under  civilized  conditions  of  life,  we  are  in 
constant  contact  with  watches  and  clocks,  and  all  of  us 
who  live  in  any  measure  a  routine  life  are  frequently  re- 
minded by  the  mere  progress  of  our  work  of  the  amount 
of  time  which  has  elapsed.  The  bodily  rhythms  serve  a 
similar  purpose.  Hunger,  for  example,  does  not  allow  us 
long  to  forget  the  accustomed  periods  for  our  meals.  The 
changes  of  light  and  temperature  which  mark  the  sun's 
daily  course  give  us  other  indications  of  time.  For  the 
longer  periods,  such  as  the  week,  the  month,  and  the  year, 
we  rely  upon  various  indirect  measures,  although  the  two 


SENSE  PERCEPTION  133 

latter  named  intervals  are  marked  more  or  less  definitely, 
the  one  by  the  shifting  phases  of  the  moon,  the  other  by 
the  climatic  changes  incident  to  the  rotating  seasons. 

Though  in  ordinary  circumstances  we  have  neither  op- 
portunity nor  need  for  judging  brief  intervals  directly,  we 
find  that  when  we  set  up  experimental  conditions  we  can 
judge  most  accurately,  if  we  are  permitted  to  use  sensa- 
tions of  hearing  and  movement  to  measure  off  the  time. 
Thus  a  series  of  rapidly  succeeding  sounds  can  be  judged 
more  accurately  than  a  series  of  flashes  of  light.  All  such 
direct  time  judgments  are  periodic,  that  is  to  say,  we  break 
up  a  time  interval  into  a  series  of  'moments.'  These 
moments  are  not  like  the  geometrical  points,  i.e.,  places 
without  size.  They  are  real  durations,  and  may  extend 
from  a  fraction  of  a  second  to  several  seconds  in  length. 
Whatever  the  actual  length  of  such  a  moment,  we  treat  it 
as  a  unit,  and  in  comparing  directly  one  time  interval 
with  another  we  judge  whether  or  not  one  of  these  units 
is  longer  or  shorter  than  another,  or  whether  there  are 
more  or  less  of  such  units  in  a  total  interval. 

Perception  of  Accent  and  Rhythm. — Our  judgment  of 
these  immediately  sensed  time  intervals  is  closely  related 
to  our  perception  of  rhythm,  in  which  evidently  both 
duration  and  accent  are  involved.  Here  again  hearing  and 
movement  are  paramount,  although  there  seems  good  rea- 
son to  believe  that  vision,  too,  may  contribute  something. 
Our  estimate  of  the  duration  of  one  interval  in  comparison 
with  another  is  much  affected  by  this  fact  of  accent.  An 
interval  bounded  by  two  loud  sounds  seems  shorter  to  us 
than  an  equal  interval  bounded  by  weak  sounds. 

For  certain  of  the  arts,  for  example,  music,  poetry,  and 
dancing,  it  would  be  quite  impossible  to  over-estimate  the 


134  AN  INTRODUCTION  TO  PSYCHOLOGY 

significance  of  rhythm.  In  a  sense  these  arts  are  simply 
the  soul  of  rhythm  embodied  in  different  kinds  of  sensory 
media.  But  so  far  as  concerns  the  apprehension  of  time, 
it  is  fairly  clear  that  while  we  are  always  more  or  less  con- 
scious of  its  passing,  we  tend  to  make  the  great  mass  of 
our  judgments  about  it  indirectly  and  by  means  of  arti- 
ficial indices.  Only  when  we  are  overcome  by  the  tedious- 
ness  of  a  situation,  do  we  tend  to  become  vividly  aware  of 
the  mere  fact  of  time  itself.  Five  minutes  spent  in  inter- 
esting work  passes  literally  before  one  knows  it.  The  same 
interval  spent  in  a  dingy  railway  station,  waiting  for  a 
train,  takes  on  fairly  portentous  dimensions.  One  never 
knows  just  how  serious  a  trial  it  is  to  be  bored,  until  one 
encounters  such  an  experience. 

Conditions  Affecting  Apparent  Length  of  Intervals. — 
Attention  has  often  been  drawn,  and  with  good  reason,  to 
the  change  of  attitude  which  we  undergo  as  we  grow  older 
toward  the  commoner  time  intervals  of  daily  life.  In 
childhood  the  year  appears  an  interminable  prospect, 
spreading  out  in  the  dim  distance  ahead.  The  month 
affords  in  its  turn  a  majestic  outlook.  Even  the  week  is 
big  with  possibilities,  and  the  day  itself  is  not  to  be  taken 
lightly,  especially  that  part  of  it  dedicated  to  the  strenu- 
ositics  of  the  schoolroom.  In  later  life  the  perspective  is 
wholly  altered.  Not  only  when  we  look  backward,  but  even 
when  we  turn  our  gaze  forward,  the  year  becomes  more 
and  more  a  trifle,  affording  only  grudging  opportunity  for 
the  accomplishment  of  the  absolutely  essential  thing.  The 
shorter  intervals  tend  to  get  wholly  lost.  To  be  sure,  in 
some  tedious  lives,  especially  those  which  are  lived  under 
the  shadow  of  ill-health,  the  month  and  the  week  may  take 
on  more  impressive  dimensions,  but  even  so,  as  contrasted 


SENSE  PERCEPTION  135 

with  the  conditions  in  childhood,  all  these  intervals  tend  to 
shrink. 

In  general,  this  phenomenon  seems  to  be  due  to  the 
increasing  domination  of  routine  in  our  lives,  and  to  the 
monopolizing  of  our  attention  in  the  mere  execution  of  the 
daily  obligations  of  life.  In  childhood  the  world  is  fresher, 
anticipation  is  more  often  whetted,  the  future  is  more 
uncertain,  preoccupation  is  less  intense  and  prolonged. 
All  these  factors  make  for  a  more  vivid  sense  of  the  pass- 
ing of  time  and  tend  to  interrupt  it  more  frequently  in 
the  mood  of  uncertain  prospecting. 

Another  peculiarity  of  our  estimates  of  time  which  de- 
serves mention  relates  to  our  memory  of  the  length  of 
intervals,  depending  upon  the  manner  in  which  they  were 
passed.  It  is  a  common  experience,  for  example,  that 
despite  the  tedium  of  prolonged  illness,  we  carry  away  in 
memory  no  vivid  recollection,  as  a  rule,  to  make  such 
intervals  seem  long  in  retrospect.  We  well  remember  that 
we  were  bored  to  the  verge  of  distraction,  and  that  it  often 
seemed  as  though  the  morrow  would  never  come.  But  in 
retrospect  it  all  shrinks  completely  out  of  resemblance  to 
its  original  dreary  length.  On  the  other  hand,  intervals 
which  pass  like  a  flash  when  we  are  keenly  interested  and 
absorbingly  preoccupied  loom  in  memory  as  very  long. 
This  inversion  of  the  memory  estimate  of  a  time  interval 
as  compared  with  our  appreciation  of  it  when  in  progress, 
obviously  relates  itself  to  the  fact  that  in  retrospect  an 
interval  is  likely  to  seem  long  or  short  depending  upon 
whether  we  can  give  it  much  or  little  content,  can  read 
back  into  it  few  or  many  events. 

Peculiar  Forms  of  Time  Judgment. — A  curious  phe- 
nomenon which  has  often  attracted  attention  consists  in 


136 

the  ability  which  some  individuals  possess  to  tell  the  time 
with  quite  extraordinary  accuracy  without  appealing  to 
watch  or  clock.  The  most  skilful  individuals  can  do  this 
even  when  awakened  out  of  sound  sleep  in  the  middle  of 
the  night.  It  is  often  combined  with  the  ability  to  awaken 
from  sleep  automatically  at  any  hour  desired.  We  are  at 
present  rather  in  the  dark  as  to  the  exact  mechanism  by 
which  these  results  are  achieved.  Eecent  experiments  indi- 
cate that  a  considerable  group  of  factors  may  be  involved, 
some  of  which  are  employed  by  one  individual  and  some 
by  another.  If  the  subject  be  wakened  in  the  night,  his 
judgment  of  the  hour  may  be  based  on  the  feelings  of 
fatigue  or  freshness,  or  on  the  number  of  dreams  since 
falling  asleep,  etc.,  etc.  But  for  some  gifted  individuals 
the  judgment  is  direct  and  immediate  and  not  dependent 
on  any  such  data.  Reference  is  made  to  the  matter  simply 
because  it  serves  to  suggest  in  a  somewhat  impressive 
fashion  the  extent  to  which  the  organism  is  sensitive  to 
temporal  changes. 


CHAPTER  VIII 
MEMORY 

The  analysis  of  the  perception  of  time  leads  naturally  to 
a  consideration  of  those  mental  processes  by  means  of 
which  we  are  able  to  transcend  time,  to  bring  back  into 
our  minds  events  which  are  past,  and  to  project  ourselves 
in  fancy  into  the  future.  We  shall  therefore  turn  to  a 
discussion  of  memory  and  imagination,  by  means  of  which 
we  achieve  these  two  results ;  and  first  let  us  examine  the 
main  characteristics  of  memory. 

At  several  previous  points  we  have  observed  how  past 
experience  modifies  present  experience.  Instincts  reflect 
the  successful  struggles  of  thousands  of  former  genera- 
tions, and  while  it  is  not  usual  to  think  of  them  as  involv- 
ing memory  in  any  usual  sense,  they  may  be  regarded  as 
disclosing  a  form  of  racial  memory.  Similarly  we  have 
already  observed  that  in  our  perceptual  processes  we  make 
constant  use,  however  unconsciously,  of  past  experience. 
But  neither  of  these  instances  comprises  the  special  kind  of 
conscious  memory  which  we  mean  to  examine.  This  is  best 
represented  in  acts  such  as  those  in  which  we  recall  our 
whereabouts  a  few  hours  ago,  remember  what  we  said  and 
did,  who  was  with  us,  etc.  As  James  puts  it:  "Memory 
proper — is  the  knowledge  of  an  event  or  fact,  of  which 
meantime  we  have  not  been  thinking  with  the  additional 
consciousness  that  we  have  thought,  or  experienced  it 
before."  The  term  'memory'  is  generally  used  more 

137 


138  AN  INTRODUCTION  TO  PSYCHOLOGY 

loosely  than  this  in  common  parlance  and  even  in  psychol- 
ogy. It  covers  the  broad  ability  to  retain  and  recall 
former  experiences,  without  much  regard  to  the  important 
point  emphasized  in  the  last  two  clauses  of  James'  defini- 
tion. 

So  familiar  are  operations  of  this  sort  that  we  become 
quite  insensitive  to  their  altogether  miraculous  character. 
But  a  miracle  it  surely  is  that  we  should  thus  be  able 
months  and  years  after  an  event  has  passed  to  bring  it 
once  again  into  the  focus  of  the  mind's  eye. 

Retention  and  Recall. — It  appears  to  the  most  .super- 
ficial inspection  that  memory  involves  two  distinguishable 
processes,  retention  and  recall.  After  a  thought  has 
passed  out  of  the  mind,  it  may  be  absent  for  years  and 
still  at  any  time  be  within  the  range  of  recall.  When  it 
is  actually  recalled,  it  lives  again,  not  precisely  as  it  did 
at  first,  but  nevertheless  genuinely  and  in  a  way  which 
may  lead  to  practical  consequences  quite  like  those  which 
flowed  from  it  on  its  first  appearance.  If  one  asks  where 
a  thought  is  when  one  is  not  thinking  about  it,  the  ques- 
tion may  strike  the  average  individual  as  in  the  nature  of 
a  fatuous  conundrum.  In  point  of  fact  it  is  not  only  a 
perfectly  fair  question,  but  one  whose  answer  carries  with 
it  highly  significant  consequences  for  one's  general  con- 
ception of  the  nature  of  the  mind.  To  discuss  the  matter 
in  detail  is  hardly  practicable  within  the  limitations  set 
by  the  present  book.  Suffice  it  to  say  that  in  the  judgment 
of  the  author  the  most  convenient  way  of  thinking  about 
this  phenomenon  of  retention  is  in  physiological  terms. 
Presumably,  as  we  have  previously  seen,  the  brain  tissues 
take  up  and  preserve  modifications  impressed  upon  them 
by  sensorial  stimulations.  When  the  stimulus  is  removed, 


MEMORY  139 

the  modifications  persist,  some  of  them  tenaciously  and  for 
long  periods  of  time,  others  in  a  more  fleeting  and 
evanescent  manner.  When  the  process  we  have  designated 
recall  occurs,  we  assume  that  in  some  way  or  other  these 
old  nervous  pathways  through  the  brain  are  once  more 
set  in  activity  by  impulses  traveling  over  them  and  we 
become  again  conscious  of  the  situation  earlier  experienced. 
We  shall  presently  discuss  certain  features  of  memory 
training  and  point  out  some  of  the  qualifications  of  a  good 
memory.  Obviously,  retention  and  recall  will  play  an 
important  part  in  any  such  discussion.  We  turn  first, 
however,  to  certain  other  facts  about  the  memory  process. 

Forgetting  as  a  Factor  in  Memory. — Contrary  to  the 
common  impression,  forgetting  is  really  a  very  essential 
part  of  effective  remembering,  but  one  must  choose  with 
intelligence  that  which  is  to  be  discarded.  Obviously,  if 
our  memories  were  freighted  with  the  entire  mass  of 
trivial  details  of  daily  life  we  should  be  swamped.  As 
a  matter  of  fact,  when  we  recall  any  ordinary  episode,  we 
get  a  highly  schematic  and  abbreviated  recollection  in 
which  as  a  rule  only  the  more  important  aspects  present 
themselves.  All  the  rest  has  disappeared,  and  unless  it  be 
essential  for  the  purposes  in  hand,  it  will  not  ordinarily  be 
revived.  The  kind  of  forgetting  which  naturally  attracts 
our  attention  is  that  which  impedes  or  cripples  our  con- 
duct, because  we  cannot  at  the  appropriate  moment  recall 
just  the  required  information.  As  compared,  however,  with 
the  great  body  of  the  phenomena  of  forgetting,  these  cases 
are  trifling  in  amount. 

Many  interesting  studies  have  in  recent  years  been  made 
showing  something  of  the  manner  in  which  forgetting  pro- 
ceeds, and  here  again  ordinary  impressions  are  apt  to  be 


140 

quite  wrong.  Figure  48  illustrates  graphically  the  rate  at 
which  a  process  of  forgetting  goes  forward.  If  one 
memorizes  a  list  of  numbers  so  that  they  can  just  be  suc- 
cessfully repeated,  the  process  of  forgetting  proceeds  most 
rapidly  in  the  first  few  hours  after  the  act  of  learning. 
Then,  as  the  curve  shows,  the  process  tends  to  slow  up  until 
finally  a  point  is  reached,  after  which  it  becomes  practically 
impossible  to  measure  the  further  loss.  Most  people  sup- 


100* 


5 24  48  144  720 

FIG.  48. — Curve  of  forgetting  based  on  Ebbinhaus'  study  of  memory 
for  nonsense  syllables  memorized  to  the  point  where  they  could 
be  correctly  repeated  once.  The  vertical  line  represents  the 
percentage  of  the  material  recalled  after  lapse  of  increasing 
intervals  of  time  indicated  on  the  horizontal  line,  to  wit,  1,  9, 
24,  48|  144,  720  hours  respectively.  The  curve  for  material 
conveying  meaning  and  not  learned  verbatim  would  be  quite 
different.  Under  such  conditions  association  of  various  kinds 
enters  to  modify  the  permanency  of  the  memory  far  more  than 
in  the  case  of  nonsense  material,  although  even  there  it  can 
be  shown  to  exercise  some  effect  in  increasing  the  duration  of 
retention.  (Modified  from  Pillsbury.) 

pose  that  there  is  very  little  forgetting  immediately  after 

the  completion  of  such  a  learning  process,  but  a  little 

experimentation  will  disabuse  the  mind  of  this  conviction. 

Distribution   of   Effort   in    Memorizing. — Clearly   this 


MEMORY  141 

fact  has  important  implications  for  students  who  are 
attempting  to  master  new  subjects  that  call  for  verbatim 
memorizing.  There  is  a  considerable  amount  of  sup- 
plementary experimentation  dealing  with  other  aspects  of 
this  same  matter,  tending  to  show  that  the  distribution  of 
one's  effort  is  a  matter  of  prime 'consequence,  not  only  in 
the  economizing  of  time  and  energy,  but  also  in  the  secur- 
ing of  permanent  results.  These  experiments  relate  not 
only  to  the  mastery  of  intellectual  materials,  such  as  would 
be  represented  in  ordinary  college  studies,  but  also  to  the 
acquirement  of  acts  of  skill,  involving  muscular  dexterities 
of  various  kinds.  Experiments  have  thus  been  made  deal- 
ing with  the  acquirement  of  a  language,  as  an  illustration 
of  an  ordinary  intellectual  task.  Others  have  dealt  with 
the  attainment  of  skill  in  the  throwing  of  balls,  in  the 
shooting  of  arrows,  in  the  mastery  of  the  typewriter,  and 
so  on.  Although  the  precise  time  relations  naturally  vary 
with  the  special  task,  all  the  experiments  tell  the  same  gen- 
eral story  in  making  clear  that  there  is  a  very  wide  choice 
among  the  various  methods  of  distributing  one's  attempts 
to  learn. 

All  students  are  familiar  with  the  process  of  cramming, 
by  means  of  which  even  the  most  neglectful  are  sometimes 
able  successfully  to  survive  the  rigors  of  an  examination. 
There  can  be  no  doubt  that  for  practically  all  persons,  and 
for  some  favored  souls  in  high  degree,  it  is  possible,  by 
the  devotion  of  a  closely  sustained  effort  of  memory  cover- 
ing many  hours  just  preceding  an  examination  (if  it  be 
of  the  type  chiefly  testing  accuracy  of  recall),  to  carry 
a  sufficient  body  of  facts  in  mind  to  come  through  the 
ordeal  with  some  vestige  of  credit.  Meantime,  for  the 
great  majority  of  persons  there  is  equally  no  question  that 


142  AN  INTRODUCTION  TO  PSYCHOLOGY 

matter  memorized  under  these  conditions  is  lost  almost  as 
rapidly  as  it  is  gained.  Exceptions  must  be  made  for  the 
occasional  individual  who  can  under  these  conditions  not 
only  learn  rapidly,  but  retain  the  facts  acquired  with 
moderate  tenacity.  Indeed,  it  may  be  mentioned  at  this 
point  that  people  may  be  divided  into  four  fairly  distinct 
memory  groups:  (1)  those  who  learn  slowly  and  retain 
well — a  not  uncommon  and  on  the  whole  a  generally  effec- 
tive type;  (2)  those  who  learn  slowly  and  forget  quickly 
(except  in  pathological  cases  not  a  very  frequent  type)  ; 
(3)  those  who  learn  quickly  and  forget  quickly,  an  ex- 
tremely common  American  type;  and  (4)  those  who  learn 
quickly  and  retain  well,  a  rare  but  bona  fide  and  eminently 
fortunate  type. 

While  it  is  impracticable  at  the  present  time  to  lay  down 
any  hard  and  fast  rules,  valid  for  all  kinds  of  work,  it  is 
quite  possible  to  indicate  the  general  principles  which 
should  be  observed  to  secure  effective  memorizing.  Obvi- 
ously, if  the  process  of  forgetting  goes  on  most  rapidly 
soon  after  the  completion  of  an  effort  at  learning,  it  will 
be  well  to  repeat  the  process  before  the  forgetting  has  pro- 
ceeded so  far  as  to  require  a  disproportionate  repetition  of 
the  original  labor.  On  the  other  hand,  a  too  long  con- 
tinued effort  will  not  only  defeat  itself  because  of  fatigue, 
but  also  because  (if  we  may  judge  the  import  of  a  con- 
siderable group  of  recognized  facts)  a  certain  amount  of 
time  is  required  for  the  modifications  impressed  upon  the 
nervous  system  to  sink  in  and  set.  If  the  attempts  at 
learning  be  so  distributed  as  to  coincide  closely  with  these 
beneficial  periods  of  'setting'  in  the  nerves,  we  shall  pre- 
sumably get  the  best  results  in  terms  of  economy  of  total 
time  and  energy  expended.  In  the  preparation  of  ordinary 


MEMORY  143 

academic  work,  these  considerations  would  lead  one,  in  con- 
trast to  the  cramming  method,  to  distribute  one's  study 
over  a  relatively  long  period  of  weeks  or  months,  with 
frequent  repetition  of  the  material  one  is  attempting  to 
master. 

The  problem  confronting  the  ordinary  college  student 
relates  to  the  arrangement  of  daily  work  rather  than  to 
the  organization  of  the  tasks  covering  a  series  of  days. 
In  this  case  exactly  the  same  doctrine  holds  true,  but  the 
foregoing  illustrations  may  perhaps  seem  to  be  less  immedi- 
ately relevant.  The  average  student  hardly  gets  over  the 
daily  assignments  once,  leave  alone  any  question  of  repeat- 
ing the  exercise,  so  that  to  urge  a  distribution  of  effort  on 
the  ground  that  a  repetition  at  interrupted  intervals  is 
advantageous  seems  somewhat  beside  the  mark.  It  is  cer- 
tainly true  that  if  the  student  cannot  so  arrange  his  work 
as  to  cover  it  more  than  once,  the  principles  under  con- 
sideration cannot  be  made  to  apply  to  him  very  obviously. 
But  in  practically  all  cases  an  industrious  student  can  go 
over  his  assignment  twice,  the  second  time  by  way  of 
review,  and  in  this  case  he  will  find  the  permanency  of  his 
retention  decidedly  enhanced  by  making  such  a  repetition 
or  review  at  a  time  separated  by  a  few  hours  perhaps  from 
his  first  encounter.  Needless  to  say,  the  peculiarities  of 
different  forms  of  subject  matter  play  a  real  part  in  such 
a  situation.  Languages,  mathematics,  and  history  are 
likely  each  to  present  certain  idiosyncrasies  not  common 
to  the  others.  Certainly  a  little  conscious  experimentation 
on  this  matter  will  be  found  of  unequivocal  benefit  by  any 
serious  student. 

Many  students,  and  among  them  generally  the  most  con- 
scientious, are  apt  to  suppose  themselves  peculiarly  vir- 


144  AN  INTRODUCTION  TO  PSYCHOLOGY 

tuous  if  they  devote  themselves  for  as  many  hours  of  con- 
secutive work  as  they  find  necessary  to  cover  a  particular 
assignment.  As  a  matter  of  fact,  this  often  results  in  a 
grotesque  waste  of  time  because  the  student 's  mind  becomes 
dull  and  tired  and  fails  to  work  at  anything  like  its  normal 
level.  It  would  be  much  more  sensible  to  interrupt  the 
work  at  that  point  where  genuine  fatigue  sets  in,  to  turn 
to  some  other  subject,  or  better  yet,  to  get  the  air  and  some 
moderate  form  of  recreation,  with  a  return  to  the  mental 
labor  itself  at  a  later  period  in  the  day.  The  moral  virtue 
which  is  no  doubt  inherent  in  the  course  described  is  unfor- 
tunately largely  negatived  by  the  psychological  viciousness 
of  the  process.  Our  schools  and  colleges  are  as  yet  very 
largely  oblivious  to  the  increased  efficiency  possible  in  the 
work  of  students  by  an  intelligent  organization  of  their 
periods  of  work.  Nor  is  it  simply  a  matter  of  efficiency ;  it 
is  also  a  matter  which  involves  fundamentally  the  joy  and 
satisfaction  of  a  proper  use  of  one's  mind. 

Typical  Defects  of  Memory. — Fallacious  memory,  as 
it  occurs  in  normal  individuals,  usually  takes  one  of  three 
forms:  (1)  facts  may  be  recalled  in  an  order  different  from 
that  in  which  they  originally  occurred,  (2)  certain  facts 
may  be  forgotten  altogether,  or  (3)  facts  which  never 
occurred  will  be  inserted  in  the  memory  of  those  which 
actually  did  happen.  These  errors  of  memory  may  all  be 
easily  verified  by  attempting  to  memorize  lists  of  eight  or 
ten  digits.  In  recall  some  of  the  digits  will  occur  in 
changed  order,  some  will  be  omitted  altogether,  and  others 
will  drop  out  and  substitutes  present  themselves  quite 
without  the  knowledge  of  the  experimenter. 

Certain  diseases  of  memory  give  us  an  interesting  insight 
into  the  principles  of  its  organization.  In  the  disease 


MEMORY  145 

known  as  dementia,  there  is  practically  a  complete  loss  of 
memory.  The  same  thing  is  met  with  in  the  case  of  shock 
as  the  result  of  an  accident,  like  a  railway  collision.  Even 
severe  emotional  shock,  caused  for  example  by  the  unex- 
pected receipt  of  bad  news,  may  produce  this  result.  Aged 
people  come  in  time  to  suffer  from  much  the  same  complete 
destruction  of  memory. 

Partial  destruction  of  memory  may  be  illustrated  by 
cases  which  affect  either  (1)  a  special  segment  of  time, 
or  (2)  soiro  special  group  of  subjects,  or  (3)  the  imagery 
connected  with  a  particular  sense.  After  an  accident,  per- 
sons are  often  unable  to  recall  anything  which  occurred  for 
several  hours  preceding  the  event  and  for  appreciable 
intervals  of  time  thereafter.  In  this  case  the  loss  affects 
information  of  every  kind  covered  by  the  period  of  time 
involved.  Quite  different  from  this  is  the  loss  of  memory 
for  music,  or  for  a  foreign  language.  Here  there  is  no 
question  of  a  special  interval  of  time;  the  defect  relates 
entirely  to  an  interconnected  subject  matter.  Again,  there 
may  be  a  more  or  less  complete  loss  of  visual  images,  so 
that  one  cannot  recall  the  appearance  of  objects.  These 
facts  suggest  the  various  kinds  of  bonds  which  hold 
memories  together. 

The  disintegration  of  memory  in  old  age  already  men- 
tioned is  a  familiar  phenomenon  closely  related  to  the  facts 
just  described.  One  of  the  first  groups  of  memories  to 
disappear  is  that  of  proper  names.  Odd  as  it  may  appear, 
abstract  ideas  seem  to  be  more  tenaciously  retained  than 
those  of  a  more  concrete  character.  In  any  event,  this  is 
true  of  the  words  which  we  use  to  designate  such  ideas. 
Nouns  tend  to  disappear  in  advance  of  adjectives  and 
verbs.  This  may  mean  that  we  use  the  latter  oftener  and 


146  AN  INTRODUCTION  TO  PSYCHOLOGY 

in  more  varied  connections,  so  that  we  have  a  larger 
reservoir  of  experiences  upon  which  to  draw.  Perhaps  it 
means  that  we  can  conveniently  use  other  kinds  of  memory 
material  for  the  objects  designated  by  nouns,  and  that  in 
consequence  our  verbal^  memory  for  them  is  not  so  well 
drilled.  Thus  we  can  recall  the  appearance  of  a  table  by 
means  of  a  visual  image.  Whatever  the  explanation,  the 
facts  are  as  we  have  stated.  Elderly  people  are  also  often 
forgetful  of  very  recent  events,  while  recalling  with  great 
vividness  the  experiences  of  childhood.  This  fact  is  no 
doubt  due  to  the  loss  of  plasticity  in  the  brain  for  new 
impressions. 

The  Conditions  of  a  Good  Memory. — "A  good  memory 
.  .  .  would  seem  to  depend  upon  (1)  ease  and  rapidity  of 
acquirement,  (2)  permanency  of  retention,  and  (3)  the 
ability  to  recall  information  promptly  and  accurately  when 
wanted.  These  results  clearly  involve  (a)  the  original  act 
of  impression,  (b)  the  process  of  retention,  and  (c)  the  act 
of  recollection.  The  original  impression  and  the  act  of 
recollection  are  under  our  immediate  control.  The  process 
of  retention,  once  a  stimulation  is  given,  depends  upon  the 
brain  tissues,  whose  condition  we  can  improve  only  indi- 
rectly by  giving  ourselves  healthful  habits  and  hygienic 
surroundings. ' ' 

So  far  as  concerns  the  original  act  of  impression,  it  is  in 
the  highest  degree  essential,  if  memory  is  to  be  accurate 
and  tenacious,  that  there  shall  be  the  greatest  possible  con- 
centration of  attention.  There  can  be  no  reasonable  ques- 
tion that  the  variations  in  the  efficiency  of  the  memories  of 
different  individuals  are  largely  occasioned  by  their  differ- 
ent powers  or  habits  of  concentrated  attending.  We  give 
concentrated  attention  naturally  to  things  which  interest 


MEMORY  147 

us  and  to  things  which  are  emotionally  exciting.  We  have 
also  to  some  degree  the  power  through  sheer  effort  of  will 
and  resolution  to  focalize  our  attention  for  a  time  even  upon 
subjects  which  are  per  se  neither  interesting  nor  exciting. 
The  attention  given  to  a  considerable  part  of  the  ordinary 
student 's  work  is  likely  to  have  in  it  something  of  this  more 
or  less  heroic  mastery  of  one's  mind,  but  it  is  obviously 
vastly  easier  to  attend  where  our  interest  is  sincerely  en- 
listed, and  it  is  for  this  reason  that  not  a  little  of  modern 
pedagogical  theory  has  insisted  that  education  be  so  or- 
ganized as  to  appeal  at  each  stage  to  the  natural  interests 
of  the  average  boy  and  girl. 

The  original  impression  can  sometimes  be  augmented  by 
appealing  to  more  than  one  sense  avenue,  as  when,  for 
example,  a  word  is  spelled  out  loud  and  also  written.  The 
Chinese  secure  a  form  of  intensified  attention  by  reading 
their  lessons  aloud.  Impressions  can  obviously  be  made 
much  deeper  by  repetition,  and  for  materials  which  must 
be  mastered  verbatim  continued  repetition  will  practically 
always  bring  success,  however  tedious  the  process. 

Much  more  important  in  retaining  an  impression  is  the 
association  of  one  fact  with  other  logically  related  facts. 
A  date  in  history  which  is  in  this  way  knit  up  with  a  great 
group  of  antecedent  circumstances  and  a  similar  set  of  sub- 
sequent events,  becomes  part  of  an  organized  system  of 
ideas  and  is  not  likely  to  be  lost,  unless  the  entire  group 
to  which  it  belongs  disappears. 

On  the  negative  side,  anything  which  serves  to  minimize 
distraction  will  be  helpful.  Freedom  from  disturbing 
noises,  from  draughts,  from  uncomfortable  chairs,  from 
unduly  interesting  scenes,  is  of  signal  importance. 

It  is  of  course  evident  that  while  the  points  touched  upon 


148  AN  INTRODUCTION  TO  PSYCHOLOGY 

in  the  last  few  paragraphs  all  relate  to  the  matter  of  secur- 
ing desirable  original  impressions,  the  practical  conse- 
quences for  the  memory  process  are  to  be  found  at  the 
moment  of  recall.  In  this  connection  it  will  be  remembered 
that,  earlier  in  the  chapter,  in  discussing  the  process  of 
learning  and  the  connected  process  of  forgetting,  the  sig- 
nificance for  retention  of  recency  of  stimulation  was 
pointed  out. 

No  single  procedure  which  can  be  readily  commanded  is 
likely  to  be  more  serviceable  in  securing  tenacious  impres- 
sions than  the  immediate  practical  application  of  any  item 
of  information  which  has  been  memorized.  Obviously  the 
special  kind  of  application  will  depend  upon  the  character 
of  the  information.  It  may  be  something  relating  to  the 
use  of  tools,  in  which  case  it  should  be  embodied  in  the 
actual  manipulation  of  the  tools.  It  may  have  to  do  with 
geometry.  If  so,  it  should  be  put  into  immediate  demon- 
stration with  models  or  drawings.  If  of  a  more  abstract 
character,  it  may  at  least  be  discussed  or  embodied  in  some 
written  form.  It  is  of  much  less  consequence  what  special 
use  is  made  of  it,  although  this  is  important,  than  that  it 
get  prompt  application  somewhere.  The  conception  which 
was  introduced  in  the  opening  chapters  of  the  book  would 
lead  us  to  expect  exactly  such  a  result  as  this,  because 
we  saw  that  all  our  mental  processes  take  their  rise  out  of 
conditions  of  motor  control,  and  it  is  therefore  natural  to 
expect  that  the  best  results  will  be  obtained  wherever  we 
realize  the  translation  of  sensory  and  ideational  processes 
into  effective  motor  activities. 

Transfer  of  Training. — An  interesting  question  is  sug- 
gested at  this  point.  Does  training  the  memory  in  one  sub- 
ject improve  the  memory  process  for  all  subjects  ?  Until  a 


MEMORY  149 

few  years  ago  almost  everyone  would  have  answered  this 
question  with  a  vigorous  affirmative.  Some  of  the  first 
experiments,  however,  initiated  to  investigate  the  facts  led 
to  an  equally  positive  denial.  More  careful  and  exhaustive 
experiments  seem  to  show  that  the  general  value  of  memory 
training  secured  in  any  special  field,  e.g.,  language  study, 
is  greatest  for  closely  similar  subject  matter,  that  it 
diminishes  rapidly  for  subject  matter  more  and  more  re- 
mote in  character,  but  that  some  effect  is  traceable  in  prac- 
tically any  other  task  undertaken.  The  same  thing  holds 
for  other  kinds  of  training,  e.g.,  muscular  skill,  where  one 
sometimes  encounters  negative  transfer.  A  man  who  has 
learned  to  speak  one  foreign  language  may  even  find  it 
more  difficult  to  learn  a  second  of  very  different  structure, 
than  he  would  have,  had  he  not  learned  the  first.  In  gen- 
eral, however,  any  systematic,  controlled  discipline  of  atten- 
tion seems  likely  to  leave  behind  some  positive  benefit  for 
other  forms  of  intellectual  work,  and  memory  is  no  excep- 
tion to  the  general  principle. 

Improvement  of  Retention  and  Recall. — It  has  already 
been  pointed  out  that  retention  is  primarily  a  matter  of 
the  brain  and  nervous  system,  over  which  we  have  only 
such  indirect  control  as  is  represented  by  our  ability  in  a 
measure  to  gain  and  maintain  conditions  of  health.  What 
has  been  said  about  securing  effective  original  impressions 
comprises  most  of  what  is  to  be  said  about  recall  itself.  To 
be  most  effective,  it  usually  requires  conditions  of  high 
concentration  of  attention.1  If  baffled  at  any  point,  it  must 

1  A  curious  exception  to  the  general  rule  is  found  in  the  not  un- 
common experience  of  trying  to  recall  a  forgotten  name.  The  more 
one  tries,  the  less  one  succeeds.  If  the  mind  be  directed  to  some 
other  matter,  the  name  often  comes  back  without  more  ado.  These 
cases  are  probably  due  to  temporary  blockage  in  the  synaptic  con- 


150  AN  INTRODUCTION  TO  PSYCHOLOGY 

show  itself  flexible  and  alert  to  utilize  every  trail  of  sug- 
gestion, to  neglect  quickly  those  which  are  unfruitful,  and 
to  follow  relentlessly  those  which  promise  success.  If  we 
have  built  up  our  material  on  well  organized  lines,  we 
shall  find  our  memories  commonly  serving  us  well;  but  a 
memory  which  has  never  been  subjected  to  persistent  dis- 
cipline is  always  likely  to  prove  treacherous,  both  in  fail- 
ing to  supply  that  which  is  needed  and  in  often  presenting 
wholly  fictitious  material  as  fact. 

In  this  general  connection  it  may  be  remarked  that 
hypnosis  gives  us  evidence  that  normal  recall  has  access  to 
very  much  less  memory  material  than  is  actually  preserved 
in  the  brain.  In  hypnotic  sleep  it  is  found  possible  to  tap 
reservoirs  of  memory  which  are  ordinarily  closely  sealed. 
A  rough  analogy  to  this  situation  is  perhaps  afforded  by 
the  supernormal  muscular  power  evinced  in  mania  and 
some  other  forms  of  nervous  disease,  when  the  nervous  and 
muscular  systems  are  often  forced  to  a  far  more  violent 
discharge  of  energy  than  usual. 

Mnemonic  Systems. — Certain  readers  will  have  seen 
advertisements  of  systems  of  memory  training,  and  will 
wish  to  know  something  of  their  value.  It  is  impossible  to 
enter  fully  upon  the  matter  here.  Suffice  it  to  say  that  in 
addition  to  such  considerations  as  have  been  already  re- 
hearsed, the  most  successful  systems  exploit  the  creation  of 
great  varieties  of  arbitrary  association,  by  means  of  which 
one  may  pass  from  one  fact  to  another.  A  list  of  forty  or 
fifty  words  may  thus  be  memorized  on  a  single  reading  by 
virtue  of  arranging  them  so  as  to  exploit  such  associa- 


ncctions  in  the  brain,  of  the  character,  perhaps,  of  passing  fatigue. 
Effort  of  attention  only  aggravates  the  inhibitions,  which  generally 
pass  away  of  themselves  after  a  time. 


MEMORY  151 

tions.  Four  or  five  words  will  serve  to  illustrate  the 
point.  House — chimney — smoke — tobacco — cigar — Cuba — 
Spain — King.  Other  systems  begin  by  obliging  the  user  to 
memorize  a  very  elaborate  framework,  which  then  serves 
as  the  rack  upon  which  by  means  of  these  arbitrary  asso- 
ciations are  hung  all  specific  facts  to  be  remembered.1 

It  may  be  said  in  general  of  systems  of  this  kind  that 
for  some  very  limited  purposes  they  may  be  of  real  value, 
but  as  bases  for  any  thorough  development  of  memory  they 
are  distinctly  less  useful  than  the  methods  we  have  de- 
scribed, assuming  an  equal  investment  of  time  and  energy 
in  the  process  of  training. 

1  "  Suppose  one  has  occasion  to  remember  a  great  many  unrelated 
numbers,  like  the  street  addresses  of  a  large  group  of  people.  One 
may  greatly  facilitate  such  a  feat  by  first  memorising  a  "  form," 
in  which  each  digit  is  connected  with  a  consonant,  e.g.,  the  1  with  t, 
2  with  1,  3  with  d,  etc.  The  next  step  is  to  make  a  word  easily 
suggested  by  the  person  whose  number  is  to  be  remembered,  in 
which  these  letters  shall  occur  in  proper  order.  For  example,  Mr. 
Smith's  number  is  122,  Mr.  Smith  is  tall.  The  word  tall  in  the 
number  form  means  122,  for  the  vowels  are  neglected." 


CHAPTER  IX 
IMAGINATION 

At  the  outset  of  the  previous  chapter,  we  commented 
upon  man's  remarkable  capacity  to  look  either  forward  or 
backward  far  beyond  the  limits  of  the  present  moment  of 
time.  We  then  described  certain  important  general  aspects 
of  memory.  Now  we  must  turn  to  a  discussion  of  a  more 
intimate  kind  regarding  the  psychological  material  em- 
ployed in  the  memory  process.  This  undertaking  will  be 
found  to  lead  naturally  to  a  study  of  imagination,  the 
mental  device  by  which  we  anticipate  the  future. 

Imagery  the  Medium  of  Recall. — We  have  seen  that 
we  possess  an  organic  form  of  memory  which  preserves  for 
us  as  reflex  and  instinctive  acts,  certain  useful  adjustments 
which  our  ancestors  acquired  at  some  time  in  the  remote 
past.  Much  of  this  type  of  memory  has  relatively  little  of 
the  psychological  now  in  it.  Conscious  memory  is  very 
largely  made  up  of  imagery,  that  is  to  say,  of  the  reinstate- 
ment of  sensory  experience  in  ideational  form.  Looking 
at  a  book  lying  on  the  table,  and  then  closing  the  eyes  and 
attempting  to  see  it  mentally  as  it  was  a  moment  before, 
most  people  succeed  with  reasonable  promptness  in  produc- 
ing a  mental  visual  picture  of  the  book,  which  for  many 
of  them  possesses  considerable  fidelity  of  detail,  both  as 
regards  color  and  form,  and  which  for  others,  although 
vaguer  and  less  distinct  than  the  original,  is  still  unequivo- 
cally visual  in  character.  Interesting  experiments  have 

152 


IMAGINATION  153 

shown  that  some  persons  are  able  to  project  these  visual 
images  out  into  space  and  hold  them  before  the  attention 
fixedly  enough  to  permit  comparing  them  with  actually 
present  physical  objects.  The  reader  may  readily  con- 
vince himself  by  trial  whether  or  not  he  can  achieve  this 
projection,  and  if  so,  in  what  manner  the  images  thus 
projected  differ  from  the  objects  actually  seen. 

Similarly,  if  a  melody  be  played  upon  the  piano,  many 
individuals  are  able  immediately  thereafter  to  '  hear  the 
tune  running  through  the  head.'  The  tonal  quality  of  this 
secondary  mental  experience  is  for  many  persons  perfectly 
unmistakable,  and  it  involves  what  psychologists  know  as 
auditory  imagery.  It  is  quite  likely  to  be  combined  with 
more  or  less  definite  throat  and  lip  movements,  such  as 
would  be  used  in  singing  or  whistling.  Practically  every 
sensation  may  in  this  way  be  repeated  in  the  form  of 
imagery,  although  there  is  very  great  variety  among  indi- 
viduals as  regards  their  ability  to  command  one  or  another 
form.  Certain  persons  have  a  marked  preference  for  one 
or  two  varieties  of  images,  and  may  be  quite  lacking  in 
some  or  all  of  the  others.  Generally  speaking,  vision,  hear- 
ing, and  the  kinaesthetic  senses  *  are  most  richly  repre- 
sented. 

The  cutaneous  group,  together  with  certain  organic  sen- 
sations, probably  comes  next,  with  smell  and  taste  com- 
peting for  last  place. 

In  all  cases  of  detailed  revival  of  past  experience  in 
memory,  we  make  use  of  one  or  another  variety  of  these 

1  Some  psychologists  doubt  whether  kinaesthetic  images  are  ever 
experienced,  because  they  believe  that  every  attempt  to  secure  them 
results  in  the  contraction,  slight  though  it  may  be,  of  the  corre- 
sponding muscles,  thus  arousing  kinaesthetic  sensation. 


154  AN  INTRODUCTION  TO  PSYCHOLOGY 

images  as  the  means  by  which  we  reinstate  mentally  the 
particular  event  or  fact  to  be  recalled.  This  does  not  mean, 
however,  that  we  necessarily  recall  events  by  images  cor- 
responding in  sense  quality  to  the  nature  of  the  original 
sensory  experience,  although  this  is  often  the  case.  For 
example,  the  memory  of  a  street  scene  may  come  back  in 
the  form  of  visual  images,  but  this  is  not  inevitable  and  for 
persons  who  have  but  little  control  over  visual  images,  some 
other  type  of  imaginal  material  may  be  employed.  Prob- 
ably the  commonest  substitute  imagery  is  linguistic ;  that  is 
to  say,  one  may  bring  back  in  the  form  of  words,  facts  and 
events  which  may  originally  have  been  visually  experi- 
enced. In  this  case  the  words  are  apt  to  be  embodied  in 
auditory  imagery,  or  in  the  form  of  motor  images  of  the 
movements  of  the  throat,  tongue,  and  lips  in  speaking.  The 
two  are  with  most  persons  regularly  conjoined.  This  con- 
junction is  a  natural  expression  of  the  law  of  habit,  inas- 
much as  when  we  speak,  we  necessarily  hear  our  own  voices 
and  so  set  up  an  intimate  association  between  the  motor  and 
the  auditory  linguistic  elements.  Sometimes  the  recall 
occurs  in  the  form  of  nascent  spoken  words.  We  'talk  to 
ourselves'  as  the  method  of  revival.  Again,  the  memory 
may  consist  almost  wholly  in  assuming  the  motor  attitudes 
of  the  remembered  experience.  When  we  come  to  discuss 
reasoning  processes,  we  shall  have  occasion  to  describe  in 
greater  detail  some  of  these  substitute  devices  by  which 
we  use  one  kind  of  mental  material  to  represent  another. 
It  should  also  be  added  that  some  psychologists  believe  that 
they  recall  events  by  'pure  thoughts'  having  no  imagery 
and  no  sensory  or  motor  elements  about  them.  The  present 
writer  thinks  the  evidence  for  these  imageless  memories  un- 
convincing, especially  where  any  attempt  is  made  to  recall 


IMAGINATION  155 

precise  details.  It  must  not  be  forgotten,  however,  that 
our  practical  use  of  imagery  for  any  purpose  whatever  in- 
volves our  apprehension  of  its  meaning,  and  it  is  generally 
the  meaning  and  not  the  particular  sensuous  form  of  the 
imagery  which  is  significant  and  important. 

Relation  of  Imagery  to  Anticipation  and  Imagination 
in  General. — All  that  has  been  said  about  the  use  of 
imagery  for  the  purposes  of  recall  is  equally  true  of  the  use 
which  we  make  of  it  for  purposes  of  anticipation.  When 
we  look  forward  in  making  a  plan,  we  employ  for  the  pur- 
pose mental  imagery  of  one  kind  or  another.  Many  people 
— and  the  reader  can  readily  assure  himself  as  to  whether 
this  be  true  in  his  own  experience — in  formulating  an 
itinerary  for  a  journey,  find  themselves  drawing  upon  their 
visual  imagery,  by  means  of  which  they  portray  to  them- 
selves the  scenes  which  they  expect  to  behold  and  the 
several  stages  of  their  progress.  Again,  it  is  a  fam'liar 
form  of  mental  organization  which,  if  confronted  with  the 
necessity  of  deciding  between  conflicting  lines  of  conduct, 
has  recourse  to  a  sort  of  mental  debate  in  which  auditory 
and  motor  language  imagery  is  drawn  upon  and  first  one 
side  and  then  the  other  is  defended.  This  often  goes  so  far 
that  it  ceases  to  be  purely  imaginal  and  becomes  a  sup- 
pressed but  actual  enunciation. 

Perhaps  the  most  unequivocal  instance  of  imagery  with 
which  the  ordinary  individual  comes  in  contact  is  found 
in  the  dream.  In  waking  life  many  persons  find  it  difficult 
to  be  sure  whether  they  have  any  images  at  all.  But  in 
the  dream  everybody  acknowledges  the  presence  of  imagery 
and  most  persons  can  readily  describe  it.  In  the  more 
exciting  dreams  the  vividness  of  the  experience  seems  fre- 
quently to  exceed  that  of  ordinary  waking  perceptions. 


156  AN  INTRODUCTION  TO  PSYCHOLOGY 

We  suggest,  therefore,  that  any  reader  who  finds  it  difficult 
quickly  to  identify  his  images,  turn  to  his  recollection  of 
dreams. 

The  term  imagination  is  apt,  like  the  connected  terms 
fancy  and  fantasy,  to  suggest  to  many  persons  wholly  un- 
real forms  of  experience.  Of  course,  there  is  a  sense  in 
which  this  implication  of  the  term  is  justified,  as  when  we 
speak  of  imaginary  ailments,  or  of  castles  in  Spain.  But 
this  is  a  very  small  part  of  the  psychological  story. 
Imagination,  which  is  simply  a  general  term  to  cover  our 
use  of  imagery,  is  obviously  one  of  the  basic  realities  of  our 
mental  life.  The  chief  means  by  which  we  remember  the 
past  and  anticipate  the  future  could  be  nothing  else.  The 
fact  that  we  also  use  it  occasionally  to  conjure  up  fiction 
in  no  way  lessens  its  essential  importance. 

Ideas  and  Images. — Before  going  on  to  some  of  the 
det  tils  regarding  our  methods  of  using  imagery,  it  will  be 
well  to  dwell  for  a  moment  upon  the  term  idea  and  its 
connection  with  the  -term  image. 

One  of  the  difficulties  which  the  beginning  student  of 
psychology  encounters  arises  from  the  fact  that  in  common 
language  we  speak  of  recalling  ideas,  or  of  having  ideas 
about  the  future,  while  we  say  nothing  at  all  about  images. 
Nevertheless  the  psychological  usage  is  entirely  justi- 
fiable, and  a  brief  explanation  will  make  the  matter 
clear. 

When  we  speak  of  understanding  the  ideas  in  a  book 
which  we  are  reading,  or  in  an  address  to  which  we  are 
listening,  we  imply  that  we  apprehend  the  meaning  of 
that  which  is  written  or  spoken.  Similarly,  when  we  have 
been  thinking  about  a  subject,  we  often  describe  the  situa- 
tion by  saying  that '  certain  ideas  have  been  running  in  our 


IMAGINATION  157 

minds.'  In  neither  of  these  cases  do  we  have  any  occasion 
to  remark,  and  much  less  to  emphasize,  the  special  imagery 
with  which  our  minds  have  been  filled  in  the  process  of 
following  or  developing  the  particular  meaning  involved. 
But  upon  a  closer  scrutiny  of  the  actual  situation,  we  shall 
find  that  to  a  greater  or  less  degree  we  have  been  making 
constant  use  of  one  or  another  form  of  imagery,  often  with 
an  appreciable  admixture  of  sensations  arising  from  our 
motor  attitudes,  which  may  be  used  as  carriers  of  our 
meaning— re.g.,  the  attitude  of  expectancy  when  thinking 
about  an  approaching  event.  Image  and  idea  somewhat 
like  sensation  and  perception,  are,  therefore,  not  two  dif- 
ferent mental  states,  but  one  and  the  same,  described  now 
from  the  point  of  view  of  particular  sensory  texture  and 
now  from  that  of  organization  and  meaning.  If  we  wish 
to  emphasize  the  fact  of  sensuous  composition,  whether 
auditory,  visual,  or  whatever,  we  use  the  term  image ;  if  the 
meaning  of  the  imagery  is  the  important  matter  and  the 
special  sensory  texture  is  unimportant,  we  may  use  the 
term  idea.  For  ordinary  purposes,  the  latter  is  nearly 
always  the  significant  matter,  and  consequently  we  tend  to 
overlook  its  actual  basis  in  sense  perception  or  in  imagery. 
But  when  we  take  the  psychological  point  of  view,  it  be- 
comes quite  essential  to  note  and  describe  the  special  form 
in  which  the  idea  or  meaning  is  embodied.  With  this  in 
mind,  we  may  always  understand  that  when  we  speak  of 
ideas  we  are  referring  to  the  meaning  of  images  or  percep- 
tions, but  that  in  the  particular  immediate  context  the 
imagery  is  unimportant. 

A  very  common  and  fundamental  distinction,  which  is 
sometimes  thought  of  as  substantially  equivalent  to  the 
distinction  between  memory  itself  and  imagination,  is  that 


158     AN  INTRODUCTION  TO  PSYCHOLOGY 

between  the  productive  and  the  reproductive  forms  of 
imagination.1 

Reproductive  Imagination. — In  so  far  as  an  image 
substantially  copies  previous  sensation  or  some  other  ante- 
cedent image,  it  would  be  designated  as  reproductive.  The 
usual  notion  of  memory  involves  some  such  direct  and  un- 
modified recurrence  of  an  original  experience.  As  a  matter 
of  fact,  probably  no  image  is  ever  in  any  absolutely  literal 
sense  a  mere  copy  of  a  previous  experience.  Differences  of 
detail,  to  mention  only  a  single  point,  are  almost  invariably 
present.  Nevertheless,  were  we  to  compare  the  sum  total 
of  our  images  with  our  past  experience,  we  should  find 
many  so  closely  resembling  the  sensory  originals  from  which 
they  spring,  that  we  should  naturally  regard  them  as 
copies.  On  the  other  hand,  many  images  are  clearly  com- 
binations of  two  or  more  originals,  while  in  the  case  of  still 
others  we  find  it  practically  impossible  to  trace  their 
sources. 

All  verbatim  memory  clearly  involves  reproductive 
imagery,  but  as  has  been  intimated  earlier  in  the  chapter, 
we  may  use  vicarious  memory  materials  which  would  not 
in  any  usual  sense  be  called  reproductive.  It  is  thus  quite 
possible  to  recall  an  event,  such  as  an  automobile  trip, 
largely  through  the  medium  of  auditory-motor  word  im- 
agery, despite  the  fact  that  the  most  impressive  events 
which  now  come  back  into  the  mind  were  themselves  of 
visual  character.  Imagery  used  in  this  way  evidently  can- 
not be  said  in  any  proper  sense  to  copy  the  original  expe- 
rience as  visual  imagery  perhaps  might  do.  It  is  rather 
symbolic  in  character,  it  represents,  or  stands  for,  an 
experience  which  in  its  sensory  texture  was  quite  different 

1  Scp  James'  definition  of  memory  on  page  137. 


IMAGINATION  159 

from  the  imagery  employed  in  its  recall.  Words,  through 
whatever  imaginal  channel  recalled,  are,  in  the  nature  of 
the  case,  almost  invariably  symbolic  so  far  as  concerns  the 
objects,  acts,  or  events  to  which  they  refer.  Thus  the  word 
'dog,'  whether  it  be  seen  or  heard  or  spoken,  whether  it 
come  into  the  mind  as  a  sensorial  or  an  imaginal  process, 
bears  no  more  resemblance  to  the  actual  animal  so  named, 
than  it  does  to  any  other  object  whatsoever.  It  is  a  mere 
symbol  and  the  French  word,  chien,  or  the  German  word, 
Hund,  will  serve  the  purpose  quite  as  well,  although  neither 
bears  the  remotest  resemblance  to  the  English  word. 

Productive  Imagination. — Productive  imagination  is 
obviously  the  form  which  we  employ  for  anticipating  the 
future  and  for  freeing  ourselves  from  a  merely  slavish 
adherence  to  past  experience.  It  goes  without  saying  that 
great  scientific  inventions,  like  great  works  of  art,  rest  upon 
the  powers  of  constructive  imagination.  The  actual 
imagery  employed  may  be  of  any  kind  whatever,  although 
certain  forms  are  obviously  more  significant  than  others 
for  particular  arts,  e.g.,  visual  images  for  painting  and 
sculpture,  auditory  and  motor  for  music.  What  is  not  so 
clear,  but  nevertheless  equally  true,  is  that  all  constructive 
thinking,  from  the  most  practical  to  the  most  theoretical, 
involves  the  utilization  of  productive  imagination.  This 
matter  will  be  touched  upon  in  a  later  chapter.  The  only 
qualification  which  needs  to  be  imposed  at  this  point  relates 
to  the  generally  accepted  fact  that  practical  results  of 
crucial  consequence  occasionally  arise  as  the  outcome  of 
brain  processes  in  the  cerebrum  which  are  not  necessarily 
represented  in  the  field  of  conscious  imagination  at  all. 
The  results,  but  not  the  process  by  which  they  are  brought 
about,  appear  in  the  mental  field.  The  sudden  flashes  of 


160  AN  INTRODUCTION  TO  PSYCHOLOGY 

insight,  the  solution  of  problems  temporarily  given  up  and 
forgotten,  are  illustrations  of  the  sort  of  thing  referred  to. 

It  remains  to  examine  some  of  the  principles  determining 
the  sequence  of  the  successive  links  in  a  chain  of  thoughts 
or  images.  This  is  a  problem  which  has  interested  every 
generation  of  psychologists,  from  Aristotle  down  to  the 
present  time. 

The  Association  of  Ideas. — That  ideas  which  have  for 
any  reason  been  connected  with  one  another  in  the  past 
tend  to  hang  together,  so  that  if  one  presents  itself  to  the 
mind  the  others  tend  to  come  with  it,  has  attracted  again 
and  again  the  attention  of  even  superficial  observers.  In 
like  fashion  the  tendencies  of  ideas  to  suggest  others  which 
resemble  them  has  repeatedly  been  noticed.  Psychologists 
have  tried  on  the  one  hand  to  analyze  and  describe  all  the 
actual  principles  which  thus  unite  ideas,  and  on  the  other 
to  ascertain  if  possible  the  causes  bringing  these  results  to 
pass.  We  shall  comment  briefly  on  both  aspects  of  the 
situation. 

The  dominant  tendency  today  is  to  seek  for  an  interpre- 
tation of  association  in  terms  of  the  activity  of  the  brain 
and  nervous  system.  We  have  already  commented  upon 
the  view  that  retention  is  primarily  a  physiological  func- 
tion, a  property  of  the  nervous  system.  As  nervous  excite- 
ment is  generated  ih  the  sense  organ  by  a  stimulus  of  one 
or  another  kind,  it  is  passed  forward  through  the  central 
nervous  system  until  finally  it  makes  its  appearance  in  the 
field  of  muscular  movement.  The  precise  pathway  tra- 
versed by  such  a  nervous  impulse  will  of  course  depend 
upon  the  permeability  of  the  chains  of  neurones,  especially 
at  the  synaptic  junctions  where  one  neurone  comes  in  con- 
tact with  another.  Thus  a  stimulus  upon  the  skin  of  the 


IMAGINATION  161 

hand  may  be  immediately  converted  in  the  spinal  cord  into 
a  reflex  impulse  moving  the  hand ;  or  the  impulse  may  be 
transmitted  up  into  the  cerebral  cortex,  thence  to  reappear 
in  a  movement  of  the  entire  body.  Which  of  these  conse- 
quences follows  will  depend  upon  the  resistance  at  the 
synapses,  and  this  resistance,  other  things  equal,  will  be 
low  if  the  pathway  has  been  frequently  used  before.  In 
other  words,  previously  established  habits  will  be  influential 
in  determining  what  shall  occur. 

Presumably  the  same  principles  which  determine  the 
course  of  a  sensory  impulse  through  the  nervous  centers  to 
a  muscle,  control  the  action  of  the  cerebral  cortex  when 
thinking  of  any  kind  is  in  progress.  It  is  quite  certain  that 
the  nervous  currents  will  tend  to  flow  in  the  direction 
where  the  synaptic  resistance  is  lowest.  Clearly  a  consid- 
erable number  of  factors  may  enter  in  to  determine  these 
resistances.  For  instance,  if  an  extensive  system  of  neu- 
rones is  already  in  an  excited  condition,  the  resistance  in 
such  a  system  is  likely  to  be  lower  than  in  an  inactive 
system.  Again,  there  is  good  reason  to  believe  that  a  chain 
of  neurones  which  has  been  recently  excited  presents  a  con- 
dition of  lowered  resistance  relatively  to  other  chains  which 
have  been  more  remotely  stimulated.  Again,  the  evidence 
is  entirely  conclusive  that  such  a  chain,  if  repeatedly 
excited,  tends  to  take  on  an  almost  reflex  character.  All 
these  considerations  and  some  others  can  be  translated  into 
psychological  terms  of  imagery  and  ideas,  and  this  we  may 
at  once  proceed  to  do.  Let  it  not  be  forgotten,  however, 
that  these  principles  were  first  worked  out  by  a  study  of 
the  strictly  mental  processes.  More  recently  a  certain 
amount  of  direct  neurological  evidence  has  been  gathered, 
and  present  day  tendencies,  as  stated  above,  favor  a  rec- 


162  AN  INTRODUCTION  TO  PSYCHOLOGY 

ognition  of  the  neural  principles  as  basic  for  an  under- 
standing of  the  temporal  order  taken  by  thoughts. 

Association  and  the  Law  of  Habit. — All  the  principles 
of  association  may  be  considered  as  in  one  way  or  another 
expressions  of  the  general  law  of  habit.  Frequency  of 
connection  is  the  most  obvious  instance  of  the  principle. 
Ideas  which  have  been  frequently  united  tend  to  recall 
one  another  at  the  expense  of  less  frequently  connected 
thoughts.  The  date  1492  is  in  this  way  associated  with 
Columbus.  Intensity  in  an  experience  may  serve  to  bind 
permanently  together  psychological  elements  that  other- 
wise would  never  suggest  one  another.  The  thoughts  of 
the  several  moments  of  a  very  terrifying  experience,  e.g., 
escape  from  a  sinking  ship,  may  thus  become  permanently 
fused.  Again,  the  recency  of  a  conjunction  may  bring  it 
about  that  the  train  of  ideas  reflects  this  connection,  rather 
than  others  which  have  been  more  frequent,  and  even  some 
which  may  have  been  more  intense. 

Evidently  these  three  factors,  if  they  were  the  only  influ- 
ences at  work,  might  make  it  substantially  impossible  to 
predict  in  a  given  case  what  associations  should  actually 
dominate,  because  it  might  well  occur  that  a  particular  idea 
a  should  have  been  frequently  connected  with  6,  recently 
connected  with  c,  and  at  some  remote  time  vividly  con- 
nected with  d.  Synaptic  conditions  would  therefore  permit 
that  the  idea  a  should  lead  to  b,  c,  or  d.  Which  one  actually 
succeeds  a  will  depend  upon  the  momentary  condition  of 
the  brain,  which  we  have  no  means  of  determining.  Mean- 
time, it  is  clear  enough  that  the  sequence  of  ideas  is  deter- 
mined by  perfectly  definite  causes,  even  if  we  are  not  in  a 
position  to  state  in  a  given  case  just  what  they  are. 

Undoubtedly    among   the    most   important   determining 


IMAGINATION  163 

factors  are  our  interests,  temporary  or  permanent,  and  our 
emotional  mood.  If  our  minds  are  preoccupied  with  some 
exciting  or  entertaining  train  of  thought,  it  is  practically 
impossible  for  ideas  connected  with  wholly  different  topics 
to  arise.  Similarly  if  we  are  in  the  clutch  of  any  strong 
emotion,  only  such  ideas  as  are  relevant  to  its  course  can 
get  a  hearing,  or  indeed,  can  reach  the  field  of  conscious- 
ness at  all.  On  the  side  of  the  brain  the  presence  of  an 
emotion  or  of  an  active  interest  involves  the  activity  of 
considerable  groups  of  neurones  belonging  to  connected 
systems. 

No  account  of  association  would  be  correct  which  implied 
that  the  succession  of  ideas  one  upon  another  could  be 
explained  in  terms  of  single  ideas.  For  example,  the  fact 
that  idea  6  follows  idea  a  is  probably  never  completely  to 
be  accounted  for  by  the  presence  of  a  alone.  Certainly  in 
all  ordinary  instances  the  appearance  of  &  is  due  to  the 
entire  context  amid  which  a  appears.  Thus  the  idea  wood 
brings  up  an  entirely  different  group  of  associates  when  it 
occurs  in  connection  with  the  search  for  fuel  and  in  con- 
nection with  an  examination  of  furniture.  The  memory  of 
words  affords  innumerable  instances  of  the  same  kind  of 
thing. 

The  Association  of  Similars. — Few  forms  of  association 
have  attracted  more  attention,  and  perhaps  none  is  more 
significant  for  human  thought  processes,  than  that  of 
resemblance,  or  similarity.  The  older  writers  on  psychol- 
ogy used  to  group  the  various  forms  of  association  under 
the  headings  contiguity  in  space  and  time,  similarity,  con- 
trast, cause,  and  effect.  The  reader  will  readily  recognize 
that  we  have  already  in  substance  dealt  with  the  case  of 
contiguity  and  to  some  extent  with  that  of  cause  and  effect. 


164     AN  INTRODUCTION  TO  PSYCHOLOGY 

In  our  original  comments  upon  association  were  cited 
instances  in  which  ideas  which  had  previously  occurred 
together,  or  in  immediate  succession,  tended  to  recall  one 
another.  Associations  involving  contrast,  e.g.,  black-white, 
large-small,  etc.,  are  closely  related  to  the  cases  of  con- 
tiguity and  we  shall  not  pause  to  discuss  them,  but  a  few 
further  words  must  be  devoted  to  associations  involving 
similarity. 

It  is  in  this  type  of  associative  sequence  that  we  seem  to 
break  most  completely  with  past  experience  and  seem  to 
achieve  freshness  and  originality  in  the  order  of  our 
thought.  It  has  often  been  said,  and  probably  with  much 
truth,  that  it  is  our  wide  and  subtle  use  of  this  kind  of 
associative  nexus  which  marks  us  off  most  unequivocally 
from  the  animals.  Ideas  which  are  similar  may  recall  one 
another,  even  though  they  have  never  before  been  in  any 
way  immediately  conjoined  in  a  thought  process.  The 
resuscitation  of  ideas  which  have  been  contiguous  in  previ- 
ous experience  affords  an  obvious  illustration  of  the  opera- 
tion of  the  law  of  habit,  but  the  association  of  similars 
seems  at  first  sight  to  violate  this  principle  absolutely.  An 
instance  or  two  of  the  type  of  thing  involved  may  profitably 
be  cited. 

When  we  are  walking  on  the  street,  we  may  pass  a  person 
whom  we  know  to  be  a  stranger,  but  whose  face  we  at  once 
feel  resembles  that  of  an  acquaintance.  Sometimes  we  are 
able  to  recall  and  identify  the  suggested  individual,  but  in 
other  instances  we  may  be  quite  at  a  loss  thus  to  place  the 
resemblance.  In  such  circumstances  the  order  of  events  is 
as  follows:  (1)  perception  of  stranger,  (2)  feeling  of 
familiarity  or  resemblance,  (3)  thought  of  the  suggested 
person.  The  third  step  is,  as  we  have  just  remarked,  some- 


IMAGINATION  165 

times  wanting.  Just  the  same  sort  of  sequence  of  events 
may  occur  when  an  idea  or  an  image,  rather  than  a  per- 
ceived object,  initiates  the  train  of  associations.  Another 
type  of  oase  is  represented  by  having  one  idea  succeed 
another  in  the  mind,  whereupon  we  then  notice  a  similarity 
between  them.  For  example,  while  looking  at  a  painting, 
the  memory  of  another  suddenly  comes  into  the  mind,  and 
at  once  we  remark  their  similarity  to  one  another.  In  this 
case  the  appreciation  of  similarity  occurs  after  the  com- 
pletion of  the  association,  instead  of  as  a  preliminary  step 
in  the  process. 

The  neural  explanation  which  is  now  generally  accepted 
for  associations  of  the  similarity  type  involves  the  suppo- 
sition that  thoughts  which  resemble  one  another  involve 
brain  processes  which  at  some  point  have  identical  ele- 
ments. This  means  that  if  two  individuals  really  resemble 
cne  another  we  shall,  in  perceiving  them,  employ  to  some 
extent  identical  nervous  pathways.  Consequently,  when 
the  idea  of  one  of  them  is  again  experienced,  the  brain 
processes  involved  will  be  in  part  the  same  as  those 
brought  into  action  when  the  thought  of  the  second  comes 
into  the  mind.  There  will  thus  be  the  possibility,  from  the 
neural  point  of  view,  that  one  of  these  brain  systems  may, 
when  active,  suddenly  stir  up  the  other.  Strictly  speaking, 
such  a  process  seems  to  involve  a  departure  from  the  usual 
habitual  type  of  nervous  activity,  but  it  clearly  frees  us 
from  the  necessity  of  admitting  that  the  succession  of 
thoughts  is  frequently,  if  indeed,  ever,  altogether  and  com- 
pletely novel.  Some  connection  in  previous  experience  is 
on  this  theory  always  to  be  discerned  in  associations  of 
ideas. 

All  the  great  minds,  especially  those  of  the  scientific  and 


166  AN  INTRODUCTION  TO  PSYCHOLOGY 

artistic  kind,  are  apparently  marked  by  a  very  high  develop- 
ment of  the  capacity  of  association  of  similars.  This  is 
particularly  true  of  poets,  the  witchery  of  whose  verse  is 
often  in  large  measure  due  to  the  subtle  delicacy  of 
metaphors  resting  upon  the  use  of  resemblance,  in  forms 
wholly  foreign  to  the  prosaic  mind. 

"yet  his  eyelids 

Widened  a  little,  as  when  Zephyr  bids 
A  little  breeze  to  creep  between  the  fans 
Of  careless  butterflies:" 

Certain  it  is  that  the  great  constructive  achievements  of 
science  and  philosophy  make  the  most  drastic  demands 
upon  the  mind  for  a  large  use  of  this  type  of  association. 
It  is  also  not  without  interest  that  a  certain  variety  of 
association  of  similars  characterizes  the  thinking  of  little 
children  and  persons  with  disordered  minds.  In  these 
latter  cases  the  associations  are  devoid  of  fundamental  sig- 
nificance, and  in  consequence  lead  to  little  or  no  practical 
result.  Wit  and  humor  depend  largely  on  similarity  asso- 
ciations, with  the  pun  as  perhaps  the  lowest  form.  In 
other  words,  the  great  accomplishments  of  human  intelli- 
gence require  not  simply  the  use  of  similarity,  but  a  nice 
sense  for  the  distinction  between  those  forms  of  it  which 
are  really  pregnant  and  those  which  are  futile. 

The  Training  of  Imagery. — Attention  has  been  called 
at  an  earlier  point  in  the  chapter  to  the  fact  that  indi- 
viduals vary  as  regards  their  control  over  different  kinds 
of  imagery  and  as  regards  their  native  preferences  in  the 
use  of  one  kind  or  another  in  their  thinking.  It  will  be 
recognized  that  within  limits  there  may  well  be  consid- 
erable advantage  in  the  ability  to  use  special  kinds  of 


IMAGINATION  167 

imagery  in  the  solution  of  particular  sorts  of  problems. 
The  question  naturally  arises,  therefore,  whether  one  can 
train  imagery,  and  if  so,  how  to  go  about  it. 

The  best  experimental  evidence  seems  to  show  that  a 
very  considerable  development  of  specific  imagery  may  be 
achieved  by  the  voluntary  attempt  to  make  use  of  it,  pro- 
vided there  be  a  reasonable  body  of  it  available  to  start 
with.  One  can  thus  by  very  little  effort  develop  visual 
imagery  by  compelling  one's  self,  for  example,  to  solve 
simple  geometrical  problems  by  means  of  such  images. 
Nobody  has  as  yet  hit  upon  any  reliable  method  for  eliciting 
imagery  which  is  at  the  outset  substantially  lacking. 
Owing  to  our  ability  to  substitute  one  form  for  another, 
it  is  found  very  difficult  to  create  conditions  which  in  any 
complete  way  compel  us  to  use  a  particular  type. 

It  is  not  without  interest  in  connection  with  this  general 
question  of  training  imagery  to  note  that  the  forms  of 
imagery  which  are  preferred  do  not  necessarily  correspond 
to  the  sensory  processes  which  are  preferred.  One  may, 
for  example,  learn  most  easily  by  the  ear,  and  still  make 
little  use  of  auditory  imagery;  or  one  may  learn  most 
readily  through  the  eye  and  yet  rely  but  little  upon  visual 
imagery  for  recall. 

After  all,  the  great  point  is  that  whatever  forms  of 
imagery  one  employs,  they  shall  be  flexible  and  reliable. 
Practice  is  the  only  road  which  one  can  travel  to  secure 
these  ends. 

In  concluding  this  chapter  two  curious  groups  of  phe- 
nomena relating  to  imagery  may  be  mentioned.  The  first 
known  as  synaesthesia  might  just  as  properly  have  been 
mentioned  in  connection  with  perception. 

Synaesthesias. — When  the  ordinary  person  hears  words 


168  AN  INTRODUCTION  TO  PSYCHOLOGY 

spoken,  or  hears  musical  sounds,  the  perception  is  domi- 
nantly  auditory,  and  while  various  other  sense  experiences 
may  be  suggested  by  the  sound,  no  one  of  them  is  in  any 
way  so  vivid  as  the  auditory.  But  for  certain  persons  the 
sounds  produce  forthwith  a  consciousness  of  color.  The 
colors  are  sometimes  of  sensory  vividness.  More  often  they 
resemble  imagery  in  texture.  But  they  come  instantly  and 
blend  with  the  sounds,  and  are  native,  not  acquired.  More- 
over, they  are  substantially  constant,  the  same  shades 


10Q., 


10 


FIG.  49. 

always  occurring  with  the  same  tones  or  words.  The 
auditory-visual  synaesthesias  are  the  most  frequent,  but 
other  senses  are  sometimes  involved,  particularly  taste. 

Number  Forms. — The  second  peculiarity  has  no  single 
name  but  is  illustrated  by  the  so-called  'number  forms.' 
Sir  Francis  Galton  gives  a  most  entertaining  and  instruc- 
tive account  of  them  and  of  the  synaesthesias  in  his 
Inquiries  into  Human  Faculty.  The  number  form  is  a 
graphic  mental  picture  (see  Fig.  49)  used  by  its  possessor 
to  exhibit  numerical  relations.  The  numbers  are  mentally 
projected  in  a  sort  of  visual  frame  and  are  always  thought 


IMAGINATION  169 

of  in  this  way.  The  months  of  the  year  are  often  placed 
in  such  forms,  although  of  quite  different  shape,  and  many 
other  instances  of  the  same  tendency  might  be  cited.  The 
number  forms,  however,  by  their  amazing  variety,  intricacy, 
and  early  appearance  in  childhood  present  the  appearance 
of  being  natural  phenomena,  not  invented  or  consciously 
adopted,  while  most  of  the  others  suggest  artificial  inven- 
tion for  amusement,  the  adoption  of  forms  actually  seen, 
or  perhaps  involve  an  effort  to  render  concrete  in  visual 
form,  something  abstract  not  to  be  otherwise  so  easily 
memorized. 


CHAPTER  X 
REASONING 

Having  analyzed  separately  and  in  some  detail  several 
of  the  main  divisions  of  adjustive  mental  processes,  e.g., 
sensation,  perception,  memory,  and  imagination,  we  must 
now  examine  the  concrete  processes  of  actual  thinking,  in 
which  all  of  these  are  involved.  Practical  thinking  is  never 
comprised  merely  of  memory  processes  or  imaginings  or 
perceivings  taken  singly.  It  implicates  all  of  them  in  one 
way  or  another. 

Adjustment  as  Problem  Solving. — In  the  opening 
chapters  of  the  book,  we  dwelt  at  some  length  upon  the 
conception  of  organic  life  and  intelligence  as  a  process  of 
adjustment.  We  must  now  return  to  that  same  conception 
and  connect  it  with  the  process  of  thinking,  which  is 
another  name  for  problem  solving.  We  shall  turn  first  to 
a  scrutiny  of  certain  typical  forms  of  problems  which  con- 
front us  in  ordinary  life,  and  then  inquire  what  are  the 
usual  varieties  of  conscious  procedure  in  meeting  and  mas- 
tering such  difficulties. 

The  earliest  and  the  most  persistent  kinds  of  problems 
are  connected  with  the  immediate  maintenance  of  life.  In 
infancy  the  gratification  of  hunger  and  thirst  are  cared  for 
almost  wholly  by  reflex  activities,  which,  thanks  to  parental 
supervision,  make  practically  no  tax  upon  the  child's  own 
intelligence.  A  little  later,  however,  there  present  them- 
selves great  groups  of  problems  connected  with  the  control 

170 


REASONING  171 

of  the  bodily  muscles.  These  are  mastered  by  a  slow  process 
of  'trial  and  error'  (or  'try,  try  again,')  certain  details 
of  which  we  shall  have  occasion  to  discuss  a  little  later  in 
our  account  of  the  development  of  voluntary  control.  Pass- 
ing over  these  achievements,  we  may  come  at  once  to  the 
sort  of  problem  which  confronts  the  child  after  he  has 
learned  to  walk  and  talk  and  exercise  a  reasonable  control 
over  his  movements. 

The  earliest  forms  are  undoubtedly  those  which  involve 
the  child's  adjustment  to  his  physical  surroundings  and  to 
other  human  beings.  He  has  to  learn  by  actual  experience 
the  size  and  the  weight  of  objects ;  to  test  his  strength  and 
endurance  in  terms  of  the  resistance  afforded  by  them;  to 
learn  their  relations  to  one  another.  With  human  beings, 
he  must  master  the  intricacies  of  deportment,  and  must 
establish  a  nice  discrimination  for  the  prejudices  of  par- 
ticular individuals  in  a  position  to  punish  or  reward  him 
for  success  or  failure  in  complying  with  their  demands. 
Problems  of  these  kinds  do  not  at  the  outset  call  for  any 
very  elaborate  processes  of  reflection.  Life  is  cast  in  a 
decidedly  experimental  mold  for  the  child  at  this  stage.  He 
cannot  predict  what  will  occur,  and  he  is  thrown  back  upon 
an  actual  test,  for  the  making  of  which  he  has  abundant 
instinctive  incentive. 

The  Primitive  Tendency  to  Generalize. — The  striking 
characteristic  of  the  mental  reaction  of  the  child  in  this 
experimental  process  is  his  deeply  rooted  disposition  to 
expect  that  both  people  and  things  will  behave  in  the  future 
as  they  have  in  the  past.  He  is  an  incorrigible  generalizer, 
and  only  the  bitter  fruits  of  experience  teach  him  after  a 
time  to  cultivate  an  attitude  of  skepticism,  until  his  knowl- 
edge of  both  man  and  beast  can  be  relied  upon  for  purposes 


172  AN  INTRODUCTION  TO  PSYCHOLOGY 

of  prediction.  In  this  matter  he  is  not  unlike  primitive 
man  when  full  grown.  It  will  cost  generations  of  scientific 
training  to  breed  out  this  disposition  to  generalize  on  inade- 
quate data. 

'  Trial  and  Error '  Method  in  Thinking. — Another 
striking  feature  of  the  early  types  of  adjustive  process  is 
their  strong  tendency  toward  the  relatively  random  'trial 
and  error'  procedure.  A  little  child  confronted  by  a  gate 
which  will  not  open  is  very  likely  to  react,  much  as  a  dog 
might,  with  violent  assaults  upon  the  impeding  barrier  and 
with  little  or  no  attempt  to  discover  and  relieve  the  precise 
difficulty.  Even  at  a  later  stage,  when  the  problems  which 
present  themselves  are  more  definitely  intellectual  in  char- 
acter, there  may  be  much  of  this  same  random  trial  and 
error  method  of  arriving  at  conclusions.  In  any  event, 
practically  all  the  problems  of  early  childhood  present 
themselves  as  relatively  simple,  concrete  issues,  such  as  a 
particular  cake  to  be  secured,  a  particular  door  to  be 
opened,  a  particular  parent  to  be  cajoled.  The  solution  is 
in  turn  apt  to  be  some  relatively  simple  concrete  act,  and 
the  trick  is  to  discover  it.  In  familiar  situations,  the 
answer  may  be  given  almost  instantly  after  the  nature  of 
the  problem  is  recognized.  In  other  cases  there  is  nothing 
for  it  but  to  try  now  this  and  now  that  solution  which  may 
suggest  itself.  There  may  be  little  or  no  attempt  to  weigh 
the  probable  success  or  failure  of  any  of  the  suggestions  in 
advance  of  an  actual  test. 

The  result  of  this  type  of  thinking  is  apt  to  be  the  accep- 
tance, as  a  permanent  mode  of  procedure,  of  the  first  solu- 
tion that  comes  to  hand.  This  may  by  accident  be  the  best 
solution,  but  more  often  it  is  not,  and  thus  it  comes  about 
that  in  carrying  out  a  definite  reaction,  the  child,  like  an 


REASONING  173 

animal,  may  incorporate  and  maintain  in  it  many  quite 
useless  elements.  In  learning  to  write,  for  example,  which 
is  a  type  of  process  usually  carried  out  under  instruction, 
and  therefore  under  conditions  much  more  favorable  than 
those  we  have  been  discussing,  children  maintain  indefi- 
nitely quite  needless  contortions  of  face  and  limb,  con- 
tributing nothing  at  all  to  the  elegance  or  effectiveness  of 
their  chirography. 

Conception  and  the  Analysis  of  the  Problem. — In  all 
the  cases  thus  far  mentioned,  we  have  assumed  that  the 
problem  which  the  child  has  to  face  is  more  or  less  imposed 
upon  him  by  the  circumstances  of  the  situation.  Such  prob- 
lems are  caused  by  the  appearance  of  any  obstacles  in  the 
path  which  he  is  following,  and  whether  physical  or  mental, 
they  disclose  at  once  their  essential  nature.  A  little  later, 
quite  a  different  set  of  circumstances  is  encountered,  in 
which  it  becomes  necessary  first  to  determine  with  exactness 
the  real  character  of  the  problem  which  is  to  be  solved, 
and  thereupon  to  proceed  to  its  solution.  Social  life  is  full 
of  experiences  of  this  kind.  One  becomes  aware  that 
for  some  undefined  reason  things  are  not  going  well. 
Before  the  cure  can  be  applied,  one  must  analyze  the  situa- 
tion and  determine,  if  possible,  at  what  point  the  difficulty 
is  located.  In  many  types  of  scientific  problem  the  same 
situation  is  encountered,  and  before  one  can  move  toward 
a  solution,  one  must  first  make  sure  of  the  real  nature  of 
the  trouble. 

This  identification  of  the  character  of  the  difficulty 
plainly  consists  in  connecting  it  with  some  previous  and 
familiar  experience.  Psychologists  speak  of  this  process  as 
'conceiving'  the  situation  in  a  particular  way.  In  the 
case  of  many  purely  intellectual  problems  this  description 


174  AN  INTRODUCTION  TO  PSYCHOLOGY 

is  appropriate  enough,  but  in  cases  where  the  situation  is 
primarily  one  of  sense  perception,  as  in  the  inspection  of  a 
disabled  machine  where  one  wishes  to  discover  the  defect 
and  repair  it,  the  location  of  the  difficulty  may  not  seem 
so  naturally  to  justify  the  term  conceiving.  Nevertheless 
the  character  of  the  process  is  at  bottom  essentially  the 
same,  and  we  may  neglect  such  differences  as  arise  between 
the  wholly  ideational  and  the  partly  perceptual  forms. 

Stages  in  Problem  Solving. — To  conceive  aright  the 
difficulty  with  which  one  is  confronted  is,  then,  in  a  think- 
ing process,  the  first  essential  step  toward  a  solution.  In 
certain  very  simple  types  of  problem,  the  solution  may 
come  almost  immediately,  as  has  been  intimated  in  a  pre- 
ceding paragraph.  For  instance,  a  new  door  key  fails  to 
throw  the  lock.  It  occurs  to  us  that  possibly  it  should  be 
withdrawn  a  trifle  from  the  guard,  whereupon  it  instantly 
works.  In  more  complex  problems  (and  these  would  be 
represented  in  almost  all  the  more  serious  reflective  forms 
of  thinking),  the  correct  conception  of  the  difficulty  (which 
may  itself  be  secured  only  after  much  effort)  leads  at  once 
by  the  process  of  association,  to  a  survey  of  one  after 
another  of  the  ideas  which  are  suggested  as  possible  solu- 
tions. The  thought  process,  then,  which  has  commonly 
been  called  reasoning,  involves  as  its  first  two  stages 

(a)  the  correct  concept  of  the  problem  or  difficulty,  and 

(b)  the  securing,  by  means  of  association,  of  an  idea  which 
will  meet  the  difficulty.    Evidently  the  thought  which  gives 
us  the  solution  may  come  only  after  a  long  process,  in  which 
many  ideas  offer  themselves  and  are  turned  away  as  inef- 
fective.   This  process  of  selection  and  rejection  rests  upon 
a  psychological  activity  which  psychologists  have  generally 
designated  judgment. 


REASONING  175 

A  final  step  which  is  involved  in  an  entirely  complete 
process  of  reasoning  is  known  as  proof,  and  consists  in  the 
organization  of  one's  evidence  in  such  fashion  as  to  estab- 
lish the  correctness  of  the  solution  upon  which  one  has 
pitched.  We  shall  comment  upon  certain  phases  of  this 
matter  a  little  later  in  the  chapter.  Let  us  return  for  a 
moment  to  consider  the  first  two  stages  which  are  peculiar 
to  every  bona  fide  thinking  process. 

The  Nature  of  the  Concept. — If  we  stop  a  thought 
process  and  examine  that  part  of  it  in  which  we  are  con- 
fronted with  a  concept,  we  shall  find  that  commonly  this 
consists  in  some  significant  image  or  group  of  images.  If, 
for  instance,  in  a  geometrical  problem,  one  has  occasion  to 
use  the  concept '  triangle, '  many  persons  will  find  that  there 
arises  in  the  mind  a  more  or  less  distinct  visual  image  of 
a  triangle,  which  serves  in  the  thought  process  to  represent 
the  relations  peculiar  to  that  special  geometrical  form. 
Other  kinds  of  objects  or  relations  may  also  be  conceptually 
symbolized  by  other  forms  of  visual  imagery.  But  undoubt- 
edly far  the  most  frequent  type  of  imagery  employed  for 
thought  processes  is  linguistic.  Such  images  may  be  audi- 
tory or  visual  or  motor,  and  the  apparently  motor  forms 
may  in  fact  be  actual,  though  partly  suppressed,  enuncia- 
tions, and  not  real  images  at  all.  The  special  sensorial 
form  is  entirely  indifferent,  but  the  use  of  words  as  thought 
material  is  by  no  means  indifferent,  as  a  moment's  con- 
sideration will  clearly  disclose.  • 

Words  as  the  Material  of  Thought. — In  the  first  place, 
the  word,  in  distinction  from  the  object  or  the  relation  to 
which  it  refers,  is  relatively  free  from  the  limitations  of 
particularity.  It  can  be  used  to  cover  any  one  of  dozens 
of  particular  instances  without  prejudice  to  its  accuracy. 


176  AN  INTRODUCTION  TO  PSYCHOLOGY 

The  word  dog,  for  example,  is  as  applicable  to  the  New- 
foundland as  to  the  poodle,  to  the  terrier  as  to  the  hound, 
to  the  dog  seen  today  as  to  the  one  seen  a  year  ago.  Con- 
sequently the  word  image  'dog'  (whatever  sensorial  form 
it  appears  in)  is  measurably  free  from  any  disturbing 
limitations  of  particular  animals  or  particular  times  and 
places.  If  one  wishes,  therefore,  to  have  a  thought  symbol 
which  may  be  used  with  great  freedom  as  a  general  term, 
the  advantages  of  the  linguistic  form  over  others  are  evi- 
dent. A  moment's  reflection  will  also  make  clear  that  just 
this  kind  of  generality  in  a  concept  is  of  the  utmost  value 
in  thinking.  It  serves  to  represent  the  essential  features 
common  to  all  the  objects,  or  all  the  relations,  of  a  class 
in  a  way  which  no  single  instance  of  either  the  objects  or 
relations  could  so  conveniently  give.  There  is  no  difficulty 
in  attaching  any  desired  particularity  to  a  linguistic  image 
by  the  use  of  other  modifying  word-forms — adjectives, 
adverbs,  and  the  like. 

Again,  the  fact  that  communication  between  men  goes  on 
chiefly  in  the  form  of  words  has  an  important  bearing  on 
the  matter.  To  be  sure  gestures,  of  which  spoken  words 
are  the  most  highly  developed  form,  are  also  employed  for 
this  purpose,  as  they  are  among  animals.  By  using  lan- 
guage as  the  material  of  thought  we  carry  on  our  individual 
thinking  in  the  same  medium  which  we  use  to  communicate 
our  ideas  to  others.  Were  this  not  the  case  we  should  have 
to  translate  our  thought  back  and  forth  from  one  medium 
to  the  other.  We  should  be  obliged,  as  it  were,  to  make 
constant  use  of  two  languages,  one  for  thinking  and  one 
for  communicating.  When  we  remark  the  overwhelm  ing 
preponderance  of  social  interests  and  social  relations  in 
our  lives,  the  advantage  of  the  use  of  a  single  medium 


REASONING  177 

for  both  of  these  purposes  is  obvious.  Indeed,  some 
psychologists  maintain  that  the  thought  process  arises 
out  of  social  situations  and  would  not  otherwise 
appear. 

Other  Materials  of  Thought. — Many  people  apparently 
make  large  use  of  motor  attitudes  and  images  for  handling 
these  conceptual  situations.  To  persons  whose  thinking  is 
not  cast  in  such  terms,  it  is  hard  to  make  clear  in  just  what 
materials  such  thought  goes  forward.  But  to  revert  to  the 
illustration  of  the  triangle,  persons  of  the  motor  type 
would,  instead  of  employing  either  visual  or  verbal  mate- 
rial, find  themselves  tending  perhaps  to  make  the  move- 
ments of  the  hand  necessary  to  trace  the  triangle,  or  simi- 
larly tending  to  follow  with  nascent  movements  of  the  head 
or  eyes  the  outlines  of  the  form. 

In  any  case,  those  forms  of  imagery  (visual,  auditory, 
motor,  etc.,)  natural  to  the  individual  tend  to  dominate 
his  method  of  thought.  Experiments  have  shown  with  es- 
sential conclusiveness  that  an  individual  may  use  one  type 
of  imagery  for  one  kind  of  problem,  and  quite  another 
type  for  problems  of  a  different  sort.  The  writer,  for 
example,  in  trying  to  solve  a  geometrical  problem  without 
the  use  of  pencil  and  paper  inevitably  falls  back  upon 
visual  imagery,  constructing  in  his  mind  just  such  figures 
as  he  would  actually  draw  if  the  materials  were  at  hand. 
But  in  dealing  with  a  problem  involving  consideration  of 
some  academic  issue,  e.g.,  the  point  at  which  modern  lan- 
guages may  best  be  introduced  into  the  school  curriculum, 
his  thinking  would  tend  to  take  the  form  of  auditory-motor 
language  imagery.  There  would  be  a  sort  of  mental  debate 
carried  on.  Peculiarities  of  this  kind  will  serve  to  illus- 
trate the  difficulty  of  making  any  sweeping  statement  about 


178  AN  INTRODUCTION  TO  PSYCHOLOGY 

the  predominance  in  a  given  mind  of  any  one  kind  of 
imagery. 

In  actual  thinking,  our  ideas  are  apt  to  move  forward 
so  rapidly  that  it  is  often  difficult  to  be  sure  what  forms 
of  thought  material  are  being  used.  But  a  little  introspec- 
tive practice  will  readily  identify  them,  especially  if  one 
select  for  examination  processes  in  which  one  is  dealing 
with  very  difficult  issues  where  the  progress  is  slow. 

Non-Conscious  Elements  in  Problem  Solving. — It  may 
perhaps  be  mentioned  at  this  point  that  a  highly  important 
part  of  many  thinking  processes  is  in  no  proper  sense  con- 
scious at  all,  but  is  cerebralistic,  or  physiological.  This 
applies  perhaps  more  to  the  stage  of  the  mental  operations 
next  to  be  mentioned,  but  it  is  measurably  true  of  them  all. 
To  illustrate,  one  is  suddenly  confronted  by  a  difficult 
problem,  and  one  says :  ' '  Let  me  think  a  moment ' ' ;  where- 
upon the  brow  is  wrinkled,  the  breathing  is  checked,  and 
all  the  external  symptoms  are  those  of  profound  abstrac- 
tion, one  may  even  say  that  one  is  'thinking  hard.'  During 
the  whole  process,  so  far  as  concerns  any  strictly  conscious 
process,  the  mind  may  have  been  essentially  a  blank,  a  mere 
vacuum ;  and  yet  at  the  expiration  of  a  moment  or  two  one 
may  give  utterance  to  a  perfectly  sane  solution  of  the  prob- 
lem, or  there  may  come  into  the  mind  a  group  of  ideas  satis- 
factorily meeting  the  difficulty  for  which  one  then  seeks 
appropriate  expression.  This  kind  of  non-conscious  think- 
ing has  probably  led  certain  psychologists  to  the  belief  in 
what  they  call  'imageless  thought.'  There  is  no  objection 
to  this  phrase,  provided  it  be  not  interpreted  as  meaning 
that  we  have  a  form  of  awareness  of  meanings  which  is 
entirely  devoid  either  of  imaginal  or  of  sensory  bases.  The 
present  writer  does  not  believe  that  there  is  any  convincing 


REASONING  179 

evidence  of  this  type  of  thing,  whereas  the  subconscious 
brain  process  is  frequently  responsible  for  the  solution  of 
difficulties.  Such  solutions  are  reached  both  when  asleep 
and  when  awake. 

The  extent  to  which  thought  is  really  carried  on  in  uncon- 
scious form  is  a  subject  of  wide  disagreement.  But  not  a 
few  of  our  ablest  psychologists  are  disposed  to  urge  not 
only  that  some  of  our  thinking  is  unconscious,  but  also  that 
practically  all  of  it  which  is  fundamentally  significant  goes 
on  in  this  way.  It  is  easy  for  anyone  who  speaks  readily 
to  gain  convincing  evidence  that  the  particular  words  used 
to  express  a  thought  were  often  in  no  way  mentally  an- 
ticipated just  prior  to  their  actual  use.  The  field  of 
pathological  phenomena  is  full  of  instances  tending  to 
suggest  the  same  general  conclusion,  i.e.,  that  large  parts 
of  our  so-called  thought  processes  are  in  no  proper  sense 
definitely  conscious. 

The  Use  of  Relations,  Especially  Similarity,  in  Think- 
ing.— Arrived  at  the  second  stage  in  our  reflective  opera- 
tions, and  assuming  that  a  satisfactory  concept  of  the 
problems  has  been  formed,  we  revert  to  the  associative 
mechanism  by  means  of  which  the  conceptual  imagery 
brings  before  us  ideas  to  be  scrutinized  and  tested  as  solu- 
tions of  the  problem  confronting  us.  This  is  the  point  at 
which  the  supreme  value  of  similarity  is  encountered.  If 
we  were  confined  to  the  use  merely  of  ideas  suggested  by 
contiguity  in  previous  time  and  place,  the  solution  of  any 
given  problem  would  depend  solely  upon  whether  or  not 
our  own  past  experience  had  chanced  to  anticipate  this 
special  difficulty,  so  that  the  reexcitement  of  the  previously 
associated  ideas  might  serve  as  a  solution  in  the  present 
instance.  Thanks  to  the  use  of  similarity,  as  between  either 


180  AN  INTRODUCTION  TO  PSYCHOLOGY 

objects  or  relations,  we  are,  however,  enabled  to  transcend 
these  limitations  of  particular  time  and  place  and  to  draw 
upon  the  entire  resources  of  our  previous  life,  without  re- 
gard to  any  special  space  and  time  sequences.  This  simi- 
larity link  (covering  many  forms  of  relations)  enables  us 
by  an  essentially  creative  process  to  bring  into  context  with 
one  another  portions  of  experiences  separated  by  months 
and  even  years  of  time,  and  thus  permits  us  to  make  them 
supplement  one  another  in  the  solution  of  our  difficulties. 

In  simple  problems,  as  has  been  mentioned,  the  mere 
appearance  of  the  crucial  idea  may  carry  with  it  a  satis- 
factory solution.  This  would  be  true,  for  example,  in  any 
problem,  such  as  that  of  certain  puzzles,  where  the  solution 
consists  in  the  discovery  of  a  particular  word.  But  in  other 
problems,  there  is  often  need  for  the  selection  of  first  one 
and  then  another  idea  and  the  combining  of  these  into  a 
significant  whole,  comprising  the  complete  solution.  This 
type  of  thing  is  represented  in  many  mathematical  prob- 
lems, and  in  many  economic  and  political  issues,  where  a 
considerable  group  of  factors  and  their  mutual  relations 
to  one  another  must  be  kept  in  mind.  In  other  words,  there 
is  not  only  need  in  a  complicated  reasoning  process  for 
ready,  profuse,  and  subtle  associations,  but  a  continuous 
process  of  selection  and  rejection  is  also  indispensable  until 
the  finally  successful  combination  is  achieved. 

There  is  no  royal  road  to  success  in  this  matter,  no  ready- 
made  rules  which  can  be  learned  and  applied  forthwith. 
Practice  within  a  given  field  undoubtedly  produces  a  cer- 
tain skill,  but  unless  one's  experience  furnishes  the  requi- 
site ideas,  there  can  be  no  solution  of  the  problem;  and 
even  if  the  ideas  are  available,  for  successful  thinking  there 
must  be  a  certain  dextrous  control  of  the  processes  of 


REASONING  181 

choosing  and  rejecting.  Otherwise  the  thought  will  be 
cumbrous  and  ineffective. 

The  Habit  Element  in  Thought. — Thus  far,  our 
analysis  has  been  couched  in  terms  which  suggest  the  solv- 
ing of  particular  problems  without  regard  to  their  bearing 
upon  further  problematic  situations.  As  a  matter  of  fact, 
in  the  adjustive  processes  of  the  simple  organism,  to  which 
the  reader 's  attention  was  directed  in  the  opening  chapters 
of  the  book,  as  well  as  in  the  more  complicated  thought  of 
human  beings,  the  formation  of  habits  of  response  is  con- 
stantly in  process.  In  the  thought  process  this  fact  of 
habit  is  reflected  partly  in  the  concept  and  partly  in  certain 
'general  principles'  of  which  we  make  use. 

Attention  was  called  at  an  earlier  point  to  the  intrinsic 
organic  tendency  to  repeat  on  the  second  presentation  of 
a  stimulus  the  reaction  made  on  its  first  appearance,  pro- 
vided this  reaction  had  been  satisfactory.  This  was  spoken 
of  as  resulting  in  a  generalizing  tendency,  and  while  there 
are  no  doubt  exceptions,  there  is  also  no  doubt  that  this  is 
the  usual  rule.  The  concept  may  be  regarded  as  the  gen- 
eralized form  of  a  psychological  reaction,  and  as  such  it 
tends  in  its  turn  to  lead  to  a  definite  form  of  motor 
response.  The  concept  table  serves  as  a  cue  to  a  gen- 
eralized type  of  motor  adjustment.  It  represents  for  us  an 
object  in  whose  presence,  regardless  of  any  trifling  indi- 
vidual peculiarities,  we  can  do  certain  standard  things, 
e.g.,  write  upon  it,  serve  food  upon  it,  etc.  The  concepts 
of  all  common  classes  of  objects  render  us  similar  service, 
and  the  same  thing  is  true  of  the  concepts  of  the  more 
familiar  relations,  such  as  those  of  time  and  space.  The 
concept  above,  the  concept  below,  both  stand  for  certain 
kinds  of  motor  adjustment.  The  concept  earlier  or  the 


182  AN  INTRODUCTION  TO  PSYCHOLOGY 

concept  later  similarly  stand  for  a  certain  temporal  arrange- 
ment of  our  behavior.  In  general  it  may  be  said  that, 
although  primarily  psychological  so  far  as  concerns  the 
medium  in  which  they  exist,  concepts  are  ~bona  fide  habits 
and  tend  to  express  themselves  eventually  in  motor  forms. 

The  same  thing  is  true  of  general  principles,  e.g.,  water 
will  not  rise  above  its  source,  men  are  stronger  than 
women,  etc.  Indeed,  the  general  principle  is  really  little 
more  than  a  concept  expanded  by  verbal  means  into  a 
formula  for  conduct.  Thus,  the  principle  in  accordance 
with  which,  in  a  process  of  multiplication,  one  carries  for- 
ward toward  the  left  all  but  the  right-hand  digit  in  each 
partial  product,  is  obviously  a  rule  of  procedure  which 
rests  upon  the  conception  of  the  process  of  multiplying. 
The  general  principle  which  formulates  the  observed  rota- 
tion of  planetary  bodies  in  elliptical  orbits  is  again  an 
expression  of  a  mode  of  procedure  which  could  be  called 
a  concept  almost  as  well  as  a  general  principle.  Similarly 
the  principle  of  gravity  formulates  the  behavior  of  bodies 
in  their  mass  relations  to  one  another  in  a  fashion  which 
could  as  appropriately  be  designated  a  concept  as  a  general 
principle.  Many  instances  might  be  cited  of  the  use  of 
general  principles,  taking  them  either  from  the  range  of 
science  or  of  practical  life,  but  in  each  case  we  should  find 
the  same  thing  true. 

Following  the  example  set  by  writers  on  logic,  psycholo- 
gists have  been  wont  in  connection  with  their  analyses  of 
reasoning  to  give  some  attention  to  the  two  processes  known 
respectively  as  induction  and  deduction.  Without  attempt- 
ing to  enter  with  any  detail  upon  the  problems  thus  pre- 
sented, we  may  venture  a  few  brief  comments. 

Inductive    Thinking. — Induction    is    a    name    for   the 


REASONING  183 

process  by  which  we  arrive  at  such  general  principles  as 
those  which  we  have  just  mentioned.  The  result,  when 
attained,  evidently  has  the  value  of  a  'habit'  of  thought 
or  behavior,  which  we  are  then  able  to  use  much  as  we  do 
our  motor  habits,  in  a  more  or  less  automatic  way,  and  at 
least  without  serious  reflection.  Thus,  in  thinking  about 
the  behavior  of  physical  objects,  we  do  not  find  it  neces- 
sary to  stop  and  speculate  upon  the  tendency  of  unsus- 
pended  masses  to  fall  to  the  surface  of  the  earth.  This 
habit  of  theirs,  which  we  refer  to  gravity,  we  take  for 
granted  whenever  occasion  demands. 

There  are  various  ways  in  which  we  come  into  possession 
of  these  general  principles.  (1)  Many  of  them  are  sup- 
plied to  us  by  our  elders,  or  by  books,  in  the  process  of  our 
formal  education.  (2)  Others  we  come  gradually  to  acquire 
for  ourselves  in  a  sort  of  rough-and-tumble  mental  process 
well  represented  in  the  harsher  experiences  of  life.  With- 
out any  special  reflection  on  the  subject,  we  learn  in  this 
way  that  hot  objects  will  burn,  that  sharp  ones  will  cut, 
and  that  smooth  ones  are  agreeable  to  the  touch.  These 
experiences  we  convert  more  or  less  promptly  into  gen- 
eralized motor  reactions  as  we  have  previously  indicated, 
and  at  the  same  time  we  are  very  apt  to  translate  them 
directly  into  intellectual  terms  as  principles  to  be  used 
when  needed  in  our  thinking. 

(3)  Differing  from  both  these  methods  is  another  peculiar 
to  the  more  abstract  generalizations  of  the  sciences.  These 
are  based  upon  much  more  elaborate  trains  of  thought  and 
upon  much  subtler  inferences.  The  whole  process  involves 
a  more  specific  purpose  to  formulate  and  justify  the  prin- 
ciples involved,  than  is  the  case  in  either  of  the  first  two 
methods  by  which  we  achieve  generalizations.  Darwin's 


184     AN  INTRODUCTION  TO  PSYCHOLOGY 

establishment  of  the  evolutionary  hypothesis  in  regard  to 
organic  life  may  serve  as  an  illustration  of  this  higher  form 
of  generalization.  It  would  take  us  too  far  into  logical 
considerations  to  attempt  to  explain  the  various  grounds 
on  which  the  validity  of  scientific  inductive  inferences  has 
been  based  and  we  must  pass  on  to  other  matters. 

Deduction. — Over  against  induction  which  represents 
broadly  the  process  of  habit  formation  in  the  region  of 
thinking,  stands  deduction,  which  represents  the  applica- 
tion of  habits  already  established.  After  we  have  formu- 
lated and  demonstrated  such  a  general  principle  as  that  of 
gravity,  we  can  at  once  infer  deductively  the  behavior  of 
any  specific  set  of  masses  under  specific  conditions.  A  very 
large  part  of  our  practical  thinking  is  directed  to  determin- 
ing the  particular  principle  or  concept  under  which  a 
specific  instance  is  to  be  brought.  When  this  is  determined, 
the  consequences  follow  almost  automatically.  Nowhere, 
perhaps,  is  this  type  of  procedure  more  frequently  met 
with  than  in  the  case  of  moral  issues.  Here  we  often  find 
it  difficult  to  classify  a  particular  act.  Once  we  can  be 
perfectly  clear  that  it  is  to  be  put  under  such  a  heading 
as  'lying'  or  'stealing,'  the  practical  consequences  for  our 
thinking  or  our  conduct  immediately  follow.  But  until  we 
are  certain  what  classification  to  apply,  our  thought  is  held 
in  suspense. 

Combination  of  Induction  and  Deduction  in  Practical 
Thinking. — It  is  a  common  misapprehension  to  suppose 
that  our  thinking  is  either  exclusively  inductive  or  exclu- 
sively deductive.  In  actual  fact,  practical  thinking  com- 
monly involves  both  types  of  process  in  somewhat  intimate 
admixture.  We  make  use  of  general  principles  and  we 
set  about  the  forming  of  new  ones  all  in  the  course  of  the 


REASONING  185 

attempt  to  solve  a  particular  problem.  This  does  not  mean 
that  we  are  overtly  conscious  of  the  intention  to  apply  a 
general  principle  or  to  create  a  new  one,  but  simply  that 
in  dealing  with  practical  issues  we  do,  in  point  of  fact, 
carry  on  parts  of  our  thinking  by  way  of  applying  concepts 
and  general  principles,  and  other  parts  of  it  in  such  a 
fashion  as  to  create  the  beginning  of  a  new  general  prin- 
ciple, or  a  new  conception.  This  fact  will  be  readily 
enough  appreciated  if  it  is  compared  with  the  correspond- 
ing motor  situation,  where  in  making  use  of  an  already 
acquired  habit  like  writing,  we  employ  it  to  deal  with  a 
fresh  problem.  In  so  far  as  we  solve  this,  we  gain  posses- 
sion to  some  extent  of  a  new  capacity,  which  we  can  in  turn 
at  a  later  time  employ  more  or  less  in  the  habitual  way. 

The  Reasoning  Powers  of  Animals. — In  concluding 
this  chapter,  a  few  words  upon  the  reasoning  powers  of 
brutes  may  be  of  interest.  The  writers  of  a  generation  ago 
were  disposed  to  contrast  instinct  with  reasoning  as  two 
radically  distinct  and  essentially  opposed  characteristics. 
Sometimes  they  urged  that  brutes  were  guided  solely  by 
instinct,  whereas  man,  although  at  times  under  the  domina- 
tion of  instinct,  was  chiefly  controlled  by  motives  of  a 
rational  kind.  Always,  however,  there  have  been  portrayers 
of  animal  behavior  who  insisted  that  wild  animals  in  par- 
ticular, but  all  animals  to  some  extent,  made  use  of  proc- 
esses essentially  like  those  of  human  reason.  Few  neigh- 
borhoods are  wholly  free  of  dogs  or  cats,  which,  if  their 
owners  may  be  believed,  evince  at  times  all  but  superhuman 
intelligence.  To  be  sure,  these  Nietszchean  super-brutes 
have  rarely  been  caught  in  the  act  by  critical  outsiders, 
but  their  conduct  soon  passes  into  a  neighborhood  myth  and 
is  accepted  more  or  less  uncritically  at  its  face  value. 


186 

It  has  been  the  ungracious  duty  of  contemporary  experi- 
mental observation  to  strip  from  the  brute  world  most  of 
the  anecdotal  laurels  which  the  previous  generation  had 
accorded.  When  subjected  to  thorough-going  scientific 
observation  under  controlled  conditions,  it  becomes  quite 
certain  that  whatever  may  be  true  of  the  occasional  genitis 
among  animals,  at  least  the  rank  and  file  of  those  lower  in 
type  than  the  apes  solve  their  problems  by  methods  which 
are  in  no  sense  identical  with  those  of  reflective  human 
thought. 

The  common  method  of  conducting  such  experiments  is 
to  place  the  animal  in  a  situation  which  requires  it  to  solve 
some  simple  problem  appropriate  to  its  supposed  capacities 
and  as  closely  as  possible  simulating  the  conditions  with 
which  it  has  to  cope  in  its  natural  habitat.  This  problem 
is  generally  so  arranged  as  to  have  the  securing  of  food 
hinge  upon  its  solution.  This  would  mean,  for  example, 
that  rats  and  mice  would  be  obliged  to  find  their  way 
through  a  tortuous  set  of  paths  to  their  food  which  they 
could  not  see,  but  the  odor  of  which  could  readily  reach 
them.  Animals  of  all  degrees  of  complexity,  from  the  very 
simple  marine  animals,  like  amphioxus,  up  to  the  higher 
quadrupeds  and  the  anthropoid  apes,  including  on  the  way 
both  reptiles  and  birds,  have  been  subjected  to  experimental 
investigation. 

A  wholly  unexpected  wealth  of  new  information  has  been 
accumulated  as  the  result  of  studies  of  this  kind,  and  our 
knowledge  of  animal  instinct  and  of  many  features  of 
animal  behavior  has  been  immeasurably  enlarged.  But  at 
no  point  have  we  come  upon  conclusive  evidence  that  ani- 
mals can  in  any  definite  way  abstract  the  essential  point 
in  a  problem  and  then  bring  to  bear  upon  it  in  the  mind 


REASONING  187 

the  fruits  of  experience,  as  can  a  human  being.  Under 
experimental  conditions  at  least  the  animal  method  of  solv- 
ing a  practical  difficulty  is  substantially  that  of  blind  trial 
and  error.  Ail  kinds  of  violent  movements  are  made ;  the 
animal  runs  hither  and  yon,  attacks  the  apparatus  here, 
there,  and  elsewhere,  and  finally,  as  the  result  merely  of 
its  exuberant  muscular  activities,  it  succeeds  in  stumbling 
upon  the  solution.  In  a  human  being,  even  though  the 
problem  were  solved  the  first  time  in  some  such  manner, 
the  chances  are  that  the  solution  could  be  repeated  a  second 
time  almost  immediately.  But  not  so  with  the  animal.  The 
second  trial  may  be  somewhat  shorter,  or  it  may  be  longer. 
In  either  case  the  ability  to  reach  a  solution  with  certainty 
requires  many  repetitions  and  a  considerable  period  of 
time.  In  other  words,  the  animal  gives  no  evidence  of 
really  comprehending  the  relation  between  the  end  to  be 
reached  and  the  several  steps  necessary  to  attain  it. 

It  would  be  too  broad  a  statement  to  say  that  animals 
never  perceive  relations.  Indeed,  it  is  no  doubt  dangerous 
to  make  any  sweeping  statement  without  distinguishing  the 
different  genera  and  species  from  one  another.  For  it  goes 
without  saying  that  the  adaptive  intelligence  of  the  higher 
apes  and  of  some  of  the  other  mammals,  like  the  elephant, 
is  far  higher  than  that  of  the  reptilian  and  cretaceous 
forms.  But  after  making  due  allowance  for  these  differ- 
ences inside  the  brute  kingdom,  it  still  remains  true  that 
in  his  ability  to  analyze,  to  abstract,  and  to  generalize,  and 
especially  in  his  power  to  use  language  as  an  accessory  to 
all  these  processes,  man  so  far  excels  the  animals  as  to 
render  his  behavior  in  many  important  particulars  essen- 
tially different  from  theirs.  Of  course  one  does  not  mean 
in  a  statement  of  this  kind  to  urge  any  radical  discon- 


188  AN  INTRODUCTION  TO  PSYCHOLOGY 

tinuity  of  development  between  the  higher  animals  and 
man,  because  the  human  child  gives  abundant  evidence  in 
its  earlier  years  of  behavior  which  is  substantially  identical 
with  that  of  the  animals.  But  one  can  allege  that,  consid- 
ering behavior  as  an  expression  of  intelligence,  the  evolu- 
tionary break  between  man  and  the  animals  is  far  greater 
than  would  be  suggested  by  a  casual  observation  of  their 
anatomical  organization.  To  be  sure,  the  human  brain 
differs  in  important  particulars  from  even  the  most  highly 
developed  animal  brain.  But  the  differences  are  not  such 
as  would  ever  have  suggested  the  gross  disparities  in  intel- 
ligence, which  the  study  of  behavior  clearly  discloses. 


CHAPTER  XI 
FEELING 

Simple  Feelings. — In  our  descriptions  thus  far  of  the 
adjustive  processes  of  intelligence,  we  have  emphasized  the 
sensations  by  means  of  which  we  come  into  contact  with  the 
world  of  physical  objects  and  the  ideas  which  serve  to  rep- 
resent these  sensorial  experiences  when  the  originals  are  not 
present.  This  procedure  has  involved  a  temporary  neglect 
of  another  group  of  factors  of  which  mention  was  made  at 
the  outset,  and  to  which  we  must  now  return.  Psycholo- 
gists often  refer  to  these  as  simple  feelings,  and  although 
there  are  some  serious  objections  to  the.  term,  it  is  perhaps 
as  convenient  as  any  other,  and  may  for  the  time  being, 
at  least,  be  employed. 

When  a  stimulus  falls  upon  a  sense  organ,  it  normally 
sets  up  a  nervous  excitation  which  is  then  transmitted  into 
the  central  nervous  system,  whence  it  issues  again  as  a  mus- 
cular movement.  But  it  is  apt  to  occasion  other  conse- 
quences besides  those  thus  described.  It  is  likely  immedi- 
ately to  produce  either  pleasurable  or  painful  results.  A 
sound  thus  striking  upon  the  ear  may  be  sensed  as  agreeable 
or  as  disagreeable.  Secondarily,  the  movement  to  which 
it  gives  rise  may  be  followed  by  a  subsequent  group  of  sen- 
sations, in  their  turn  agreeable  or  disagreeable.  Thus,  a 
visual  object  stimulates  the  retina,  and  the  hand  is  extended 
to  grasp  it.  If  it  be  a  thistle,  or  a  burr,  the  disagreeable 
consequences  are  likely  to  be  extremely  vivid.  Thus  it 

189 


190  AN  INTRODUCTION  TO  PSYCHOLOGY 

comes  about  that  from  the  very  beginning  sensory  stimula- 
tions are  for  the  most  part  not  indifferent,  but  already 
come  freighted  with  prejudices,  favorable  or  unfavorable, 
to  their  repetition. 

In  the  life  of  the  lower  types  of  animals,  and  in  the 
experience  of  the  human  child,  these  psychological  factors 
apparently  play  an  extremely  important  part,  and  they 
must  therefore  be  examined  with  some  care.  In  adult 
human  life,  they  become  complicated  with  many  other  influ- 
ences, so  that  the  immediacy  of  their  operation  is  screened 
or  lost.  The  little  child  or  the  animal  will  unhesitatingly 
seek  to  repeat  the  pleasurable  stimulation  as  long  as  it 
remains  agreeable,  and  will  similarly  shrink  from  the  pain- 
ful stimulus.  The  adult  human  being,  on  the  other  hand, 
has  learned  that  it  is  the  part  of  wisdom  to  curtail  the 
repetition  of  pleasurable  experiences  before  satiety  has 
been  reached.  He  has  also  learned  that  the  endurance  of 
many  forms  of  painful  stimulation  may  be  the  price  of 
more  lasting  or  more  satisfying  future  pleasures.  In  other 
words,  experience  complicates  enormously  the  implications 
of  the  pleasure-pain  experiences  of  primitive  life. 

The  Varieties  of  Simple  Feeling. — Among  recent 
writers  there  has  been  some  divergence  of  opinion  as  to  the 
number  and  character  of  these  psychological  elements.  The 
great  majority  have  recognized  only  pleasantness  and  un- 
pleasantness (physical  pain,  as  was  pointed  out  in  Chapter 
VI,  which  may  itself  be  at  times  agreeable,  though  it  is 
commonly  disagreeable,  is  undoubtedly  a  sensation).  The 
eminent  German  psychologist  Wundt  recognizes  two  other 
groups  of  elements,  which  he  designates  strain-relaxation 
and  excitement-calm.  These  he  thinks  of  as  combining  with 
one  another  in  various  ways,  although  only  one  member  of 


FEELING  191 

each  pair  would  ever  be  present  in  a  single  moment  of 
experience.  The  American  philosopher  and  psychologist, 
Josiah  Royce,  excludes  strain-relaxation  but  accepts  the 
other  two  Wundtian  groups.  The  present  writer,  for  rea- 
sons which  he  feels  it  unnecessary  to  discuss  in  detail,  is 
disposed  to  adhere  to  the  older  view,  and  to  treat  pleasant- 
ness and  unpleasantness  as  the  only  elements  substantially 
different  from  sensation.  Indeed,  in  his  judgment  there  is 
a  good  deal  of  evidence  to  suggest,  as  not  a  few  modern 
writers  are  now  urging,  that  even  these  forms  of  experience 
are  themselves  vague,  diffused,  organic  sensations.  Even  if 
this  last  doctrine  should  finally  become  established,  it 
would  still  be  convenient  to  accord  a  separate  discussion 
to  these  factors  in  our  mental  make-up. 

Among  other  reasons,  the  view  generally  prevalent  at 
present  distinguishes  from  the  sensations  these  two  forms 
of  simple  feeling  (1)  psychologically,  because  they  may 
attach  themselves  to  any  sensation  or  idea,  and  may  vary 
independently,  so  that  the  same  stimulus  may  on  one  occa- 
sion be  felt  as  pleasurable  and  on  another  as  unpleas- 
urable;  and  (2)  physiologically,  because  they  are  thought 
of  as  arising  not  from  the  stimulation  of  a  particular  sense 
organ  with  its  connected  chain  of  neurones,  but  as  arising 
from  the  way  in  which  the  nervous  system  as  a  whole  is 
affected  by  any  momentary  stimulation.  The  alleged  fact 
that  we  do  not  localize  them  as  we  do  sensations  is  urged 
in  support  of  this  view.1 

1  Of  course  if  they  prove  finally  to  be  sensations,  they  must  depend 
upon  special  sensory  nerves  which  must  be  capable  through  some 
physiological  device  of  being  reflexly  excited  from  activities  in  the 
cerebrum,  or  in  other  parts  of  the  central  system.  The  possibility 
that  the  thalami  are  the  central  organs  responsible  for  them  would 
not  be  irreconcilable  with  this  conception.  See  page  45. 


192  AN  INTRODUCTION  TO  PSYCHOLOGY 

Explanatory  Theories  of  Feeling. — In  connection  with 
the  physiological  conception,  two  general  types  of  hypoth- 
esis have  been  advanced.  The  first  maintains  that  all 
experiences  which  are  organically  beneficial  tend  to  elicit 
pleasure,  whereas  those  which  are  physiologically  harmful 
tend  to  occasion  pain.  The  second  is  substantially  a  modi- 
fication of  the  first,  and  urges  that  pleasurable  experi- 
ences are  such  as  involve  activities  of  the  nervous  system 
well  within  the  limits  of  its  physical  powers,  whereas  un- 
pleasant experiences  involve  excessive  drain  at  one  point 
or  another  upon  the  resources  of  the  system. 

Another  widely  held  view  connects  pleasure  with  mental 
activities  which  progress  smoothly  toward  an  end,  and  dis- 
pleasure with  such  as  are  impeded  or  obstructed  in  their 
course.  Obviously  this  conception  is  most  immediately 
applicable  to  cases  in  which  the  mind  is  engaged  in 
processes  of  problem-solving  of  a  rather  definite  kind.  In 
such  instances,  we  become  readily  aware  of  differences  in 
the  ease  and  directness  with  which  our  thought  attains  its 
goal.  For  example,  a  student  trying  to  study  finds  the 
interruption  of  a  neighboring  piano  extremely  disagreeable, 
even  though  the  music  itself  be  intrinsically  pleasant.  On 
the  other  hand,  the  very  act  of  studying,  provided  the 
thought  processes  involved  go  forward  smoothly  and  effec- 
tively, is  likely  to  be  found  agreeably  stimulating.  In  such 
a  situation  the  theory  mentioned  would  find  an  explanation 
for  the  appearance  of  -agreeableness  or  disagreeableness  in 
the  absence  or  presence  of  material  interruption  to  the 
thinking. 

This  type  of  theory  finds  it  more  difficult  to  give  a  satis- 
factory reason  for  the  appearance  of  some  forms  of  sensory 
pleasantness  and  unpleasantness.  If  one  strikes  a  discord 


FEELING  193 

on  the  piano,  the  effect  may  be  markedly  disagreeable,  and 
when  one  suddenly  shifts  to  a  group  of  harmonious  tones, 
the  result  is  forthwith  pleasing.  In  both  cases  one's  pur- 
pose may  have  been  to  detect  the  qualities  of  the  tones, 
and  in  this  sense  both  processes  go  forward  more  or  less 
successfully ;  nevertheless  the  one  is  disagreeable,  the  other 
agreeable.  Similarly  there  are  degrees  of  pressure,  degrees 
of  illumination,  degrees  of  noise,  which  are  always  dis- 
agreeable. Clearly  such  cases  occasion  embarrassment  to 
theories  couched  in  the  form  of  the  one  we  are  now  dis- 
cussing. Facts  of  this  variety  evidently  lend  themselves 
much  more  readily  to  description  either  in  terms  of  the 
biological  utility  (negative  or  positive)  of  the  stimulus,  or 
in  terms  of  the  capacity  of  the  sense  organ  and  the  nervous 
system  to  respond.  Nevertheless,  while  one  may  refuse  to 
accept  a  formulation  of  the  kind  under  consideration  as 
affording  in  any  sense  a  complete  theory  of  the  conditions 
of  feeling,  one  must  frankly  recognize  that  a  very  large  part 
of  the  more  important  of  our  human  experiences  are  cor- 
rectly characterized  by  it. 

One  of  the  early  formulations  essentially  similar  to  the 
one  we  are  now  examining  connected  pain  and  unpleasant- 
ness with  a  tendency  to  change  whatever  conditions 
obtained,  and  pleasure  with  a  tendency  to  continue  such 
conditions.  This  notion  falls  in  very  readily  with  the 
general  biological  hypothesis  of  agreeableness  and  dis- 
agrecableness  as  protective  indices,  the  one  indicat- 
ing a  need  of  instant  fresh  adjustment,  the  other 
endorsing  whatever  process  is  at  the  moment  going 
forward. 

A  variant  of  this  view  identifies  pleasure  with  expansive, 
appropriative  movements,  pain  and  displeasure  with  con- 


194  AN  INTRODUCTION  TO  PSYCHOLOGY 

tractive  movements  and  movements  of  retreat.  The  formu- 
lation is  roughly  correct  in  its  application  to  simple  sen- 
sory pleasantness  and  unpleasantness,  but  cannot  be 
pressed  very  far  without  breaking  down.1 

It  must  be  frankly  admitted  that  all  these  conceptions 
are  in  a  measure  speculative  and  that  while  they  correspond 
to  certain  broad  features  of  common  experience,  they  are 
none  of  them  free  from  difficulties,  none  of  them  affords 
wholly  conclusive  explanations  of  observed  phenomena.  It 
is  hardly  to  be  supposed  that  any  species  of  animals  could 
survive,  which  sought,  rather  than  shunned,  painful  expe- 
riences, because  in  general  such  experiences  are  simply  the 
conscious  side  of  physiologically  disastrous  conditions.  Any 
creature  which  gratuitously  sought  out  the  circumstances 
productive  of  headache,  toothache,  and  earache  could 
scarcely  be  expected  to  thrive.  Clearly,  too,  a  creature 
which  was  wholly  oblivious  to  pleasurable  experiences 
could  hardly  expect  to  secure  the  best  conditions  for  its 
physical  well-being,  and  in  competition  with  other  indi- 
viduals and  species  would  almost  certainly  be  out-distanced. 
Whether  pleasure  and  pain  have,  therefore,  been  prime 
factors  in  the  development  of  animal  behavior,  it  is  at  all 
events  clear  that  they  can  hardly  have  failed  to  play  an 
important  part.  On  their  lower  levels,  they  certainly  rep- 
resent modes  of  guiding  the  organism  in  advance  of  the 

1  Wundt  alleges  that  there  are  certain  definite  and  constant 
changes  in  the  respiration  and  circulation  corresponding  to  his  six 
simple  feelings.  Some  other  psychologists  have  reported  such 
changes  for  pleasantness  and  unpleasantness.  The  present  author 
regards  the  evidence  upon  which  these  views  rest  as  open  to  grave 
doubt.  Many  competent  experimenters  have  been  unable  to  demon- 
strate any  constancy  in  the  connection  of  the  affective  mental  states 
with  the  alleged  physiological  reactions. 


FEELING  195 

lessons  of  experience  and  in  advance  of  the  development  of 
critical  intelligence. 

Complex  Feelings. — A  distinction  may  now  be  drawn 
which  logically  should  have  been  mentioned  earlier,  but 
which  seemed  likely  to  be  somewhat  more  readily  under- 
stood if  postponed  to  this  point  in  the  chapter.  This  has 
to  do  with  the  difference  between  the  simple  elements  of 
feeling,  sometimes  designated  in  the  modern  literature 
'  affection, '  and  the  complex  feelings  which  involve  not  only 
these  elements  but  sensations  and  ideas  beside.  The  simple 
feeling,  or  the  '  affection, '  is  clearly  gotten  only  by  abstrac- 
tion. We  never  experience  pure  agreeableness  devoid  of 
other  conscious  accompaniments.  What  we  experience  is 
always  an  agreeable  idea,  or  an  agreeable  emotion,  an  agree- 
able memory,  or  an  agreeable  perception.  It  is  perfectly 
possible  for  us  to  isolate  the  agreeableness  in  our  retrospec- 
tive analysis  of  any  particular  experience.  Indeed,  scien- 
tifically it  is  quite  essential  that  we  should  do  this,  for  an 
idea,  emotion,  memory,  or  perception  may  obviously  be 
experienced  either  with  an  opposite  feeling,  or  to  all  intents 
and  purposes  with  no  feeling  at  all.  Thus  it  has  come  about 
that  psychologists  who  use  the  word  feeling  as  a  technical 
term  are  disposed  to  apply  it  to  the  entire  concrete  expe- 
rience in  which  agreeableness  or  disagreeableness  is  a  con- 
spicuous element,  but  in  which  other  mental  factors  are  also 
present.  The  terms  simple  feeling,  affection,  or  feeling- 
tone,  are  then  used  to  designate  the  special  part  of  the 
process  which  is  represented  in  its  pleasantness,  unpleasant- 
ness, and  the  like.  (See  Fig.  50.) 

Strictly  speaking  one  can  hardly  classify  feelings  except 
into  such  rudimentary  groups  as  are  already  represented  in 
our  own  acceptance  of  agreeableness  and  disagreeableness 


196  AN  INTRODUCTION  TO  PSYCHOLOGY 

as  primordial  distinctions.  Despite  this  assertion,  a  good 
many  classifications  have,  as  a  matter  of  fact,  been  pro- 
posed and  adopted.  One  of  the  older  of  these  distinguishes 
higher  from  lower  feelings.  In  the  application  of  this  dis- 
tinction, it  appears  that  the  lower  feelings,  so-called,  are 
chiefly  those  connected  with  the  immediate  use  of  the  senses 
most  closely  related  to  the  nutritional  processes  (e.g.,  agree- 
able and  disagreeable  tastes  and  odors)  and  to  those  con- 
nected with  the  physical  appetites  and  passions.  The 


FIG.  50. — To  illustrate  the  relation  of  simple  feeling  to  total  feeling 
states.  8F,  may  represent  a  simple  feeling,  or  affection,  like 
pleasantness,  which  may  be  combined  with  Se,  sensory,  or  /, 
imaginal,  or  ideational,  elements  to  constitute  a  total  complex 
state  of  feeling. 

higher  feelings  are  on  this  showing  such  as  have  to  do  with 
moral,  intellectual,  and  aesthetic  experiences. 

For  some  purposes  a  distinction  of  this  kind  undoubtedly 
has  justification  and  value,  but  it  may  well  be  questioned 
whether  it  is  not  psychologically  somewhat  misleading.  The 
pleasures  and  pains  of  taste  and  smell,  for  example,  and 
those  which  are  connected  with  the  relief  of  hunger  and 
thirst,  may  be  thought  of  as  lower  than  the  pleasure  and 
pains  of  moral  experience,  because  it  may  seem  that  the 
latter  have  a  more  direct  importance  for  society  and  the 
general  character  of  human  relations.  But  if,  as  we  believe 
to  be  the  case,  the  pleasure  in  the  one  instance  is  qualita- 
tively of  the  same  kind  with  the  pleasure  in  the  other,  and 


FEELING  197 

especially  if  we  find  ourselves  obliged  to  admit  a  peculiarly 
rare  and  fine  type  of  pleasure  elicited  by  the  fragrance  of 
spring  flowers,  or  by  the  play  of  beautiful  colors  upon  the 
retina,  we  may  begin  to  call  in  question  not  only  the  psy- 
chological value,  but  also  the  intrinsic  truth  of  a  distinction 
which  sets  over  against  one  another  facts  that  are,  in  their 
inner  essence,  of  essentially  the  same  order.  We  do  not 
mean  to  assert  for  a  moment  that  there  are  not  in  such 
cases  abundant  differences  in  the  sensory  and  ideational 
settings  of  these  simple  feelings.  We  do  mean,  however,  to 
urge  strongly  that  intensity  and  duration  apart,  the  agree- 
ableness  and  the  disagreeableness  of  one  group  of  experi- 
ences is  quite  of  a  piece  with  that  of  the  other. 

Another  classification  ostensibly  different  from  that  just 
described,  but  in  point  of  fact  working  out  to  a  result  in 
many  particulars  similar,  recognizes  a  distinction  between 
sensuous  and  ideational  or  intellectual  feelings.  The  basis 
of  this  distinction  is  too  obvious  to  require  discussion,  and 
like  the  one  just  examined,  it  clearly  involves  a  division 
not  based  upon  the  feeling-tone  or  the  'affection'  as  such, 
but  simply  upon  its  cognitive  accompaniment  in  the  form 
of  sensation  or  idea. 

Again,  one  frequently  encounters  reference  to  personal 
feelings,  to  social  feelings,  to  ethical  and  aesthetic  feelings. 
All  these  divisions  are  perfectly  legitimate,  and  all  refer 
to  groups  of  experiences  which  the  exigencies  of  practical 
life,  or  of  one  and  another  of  the  philosophical  sciences, 
have  required  that  we  should  recognize.  But  to  each  and 
all,  in  so  far  as  they  are  offered  as  psychological  classifica- 
tions, the  same  comment  is  appropriate.  They  are  classi- 
fications either  of  the  conditions  under  which  certain  sorts 
of  complex  feelings  arise,  or  they  are  classifications  of  the 


198  AN  INTRODUCTION  TO  PSYCHOLOGY 

mental  concomitants  of  our  feeling-tones,  rather  than  classi- 
fications of  the  feeling  elements  themselves.  This  entire 
problem  presented  by  classification  exhibits  one  of  the 
essential  characteristics  of  pure  feeling,  which  may  now  be 
profitably  mentioned. 

Feeling,  Sensation,  and  Attention. — It  is  exactly  the 
vagueness  and  the  undifferentiated  character  of  feeling 
which  sets  it  off  from  sensation  and  idea.  So  much  so  is 
this  the  case  that  it  is  commonly  agreed  by  psychologists 
that  we  cannot  in  any  proper  sense  attend  to  a  feeling-tone. 
Certain  it  is  that,  if  in  the  midst  of  an  agreeable  experience 
one  attempts  to  fix  attention  upon  the  pleasantness  as  such, 
one  forthwith  finds  that  the  whole  experience  has  been 
transformed  and  the  agreeableness  has  evaporated  in  the 
process.  In  order  that  we  should  be  able  to  attend  to  any 
item  of  our  experience,  it  is  apparently  essential  that  it 
should  be  possible  to  discriminate  differences  within  it. 
This  is  exactly  what  we  cannot  do  in  the  case  of  these  ele- 
ments of  feeling-tone.  They  are  apparently  homogeneous, 
and  while  they  connect  themselves  in  the  most  varied 
fashion  with  all  other  psychological  materials,  they  never 
themselves  become  focal.  They  are  always,  as  it  were,  in 
the  margin  of  consciousness.  There  we  may  observe  them 
by  a  sort  of  mental  indirect  vision,  and  we  are,  in  the 
moment  of  experience,  keenly  aware  of  their  presence,  but 
to  make  them  the  objects  of  attention  is  apparently  to 
destroy  them  forthwith.  They  seem  always  to  function  as 
adjectives  or  adverbs,  which  demand  a  substantive  or  a 
verb  of  some  kind  to  which  they  may  attach. 

This  hostility  of  feeling-tone  to  attention  has  led  some 
authorities  to  the  interesting  suggestion  that  attention  and 
feeling- tone  are  really  the  two  opposite  sides  of  one  and  the 


FEELING  199 

same  process.  This  is  perhaps  another  way  of  stating  a 
much  older  doctrine,  i.e.,  that  sensations  and  ideas  give  us 
the  objective  elements  of  our  experience  which  we  can,  if 
we  will,  share  with  others.  By  looking  at  the  same  object, 
we  may  both  get  what  is  practically  the  same  sense  per- 
ception, and  we  get  this  by  a  process  of  attending.  Feeling, 
on  the  other  hand,  represents  our  purely  individualistic 
experience,  the  way  in  which  we  subjectively  react.  This 
part  of  our  experience  we  can  in  no  immediate  sense  share 
with  others.  In  any  event,  it  is  the  purely  unique  indi- 
vidual part  of  the  experience,  which  makes  it  mine  rather 
than  yours. 

Feeling  and  Personal  Attitude. — Whatever  the  final 
validity  of  such  distinctions  as  those  mentioned  in  the 
previous  paragraph,  it  is  unquestionably  true  in  a  broad, 
general  way  that  feeling  represents  in  a  very  real  and 
peculiar  sense  the  personal  mental  attitude  of  the  indi- 
vidual. In  what  one  feels  much  more  truly  than  in  what 
one  thinks  about,  is  revealed  one's  actual  character  and 
temperament.  This  is  not  equivalent  to  saying  that  a  man 's 
thought  is  in  any  way  a  matter  of  indifference  in  the 
formation  of  his  character.  It  means  simply  that  deeper 
and  more  significant  than  the  items  in  one 's  body  of  knowl- 
edge, and  even  deeper  than  the  particular  content  of  one's 
thought,  is  the  personal  attitude  toward  all  these  ideas  and 
their  meaning. 

Before  leaving  the  specialized  discussion  of  feeling,  we 
may  properly  devote  a  few  moments  to  a  consideration  of 
certain  of  its  relations  to  the  control  of  conduct. 

Feeling  and  Conduct. — We  indicated  at  the  outset  of 
the  chapter  that  one  important  view  is  committed  to  the 
doctrine  that  feeling  represents  the  primitive  guide  by 


200  AN  INTRODUCTION.  TO  PSYCHOLOGY 

means  of  which  conduct  is  "steered,  away  from  harmful  and 
toward  beneficial  types  of  reaction.  So  long  as  this  doc- 
trine is  confined  to  the  behavior  of  the  simpler  organisms 
whose  environment  is  relatively  simple,  and  whose  activities 
are  relatively  stereotyped,  it  is  likely  to  seem  plausible 
enough.  Certain  it  is  that  the  observation  of  animals  low 
in  the  scale  of  intelligence  distinctly  suggests  reactions  of 
a  reasonably  immediate  kind  in  terms  of  the  agreeableness 
or  disagreeableness  of  the  stimulus  and  the  ensuing  re- 
sponse. Fishes,  for  example,  seem  often  to  wander  about 
somewhat  aimlessly,  rejecting  whatever  food  is  offensive 
and  unhesitatingly  accepting  that  which  is  appetizing,  and 
in  the  meantime  evincing  little  or  no  evidence  of  behavior 
controlled  by  ideas  or  any  other  kind  of  process  involving 
foresight.  If  agreeable  but  poisonous  food  be  offered,  it  is 
immediately  accepted.  Behavior  on  this  level,  then,  sug- 
gests rather  strongly  that  whether  or  not  beneficial  reac- 
tions are  made  because  they  are  agreeable,  there  is  at  least 
a  general  parallelism  between  those  types  of  behavior 
which  are  apparently  satisfying  and  those  which  are  bio- 
logically useful,  with  a  corresponding  parallelism  between 
the  disagreeable  and  the  injurious. 

If  one  adopts  the  implications  of  this  general  point  of 
view  and  applies  them  forthwith  to  the  higher  ranges  of 
human  conduct,  one  instantly  comes  upon  a  doctrine  sub- 
stantially that  of  the  ethical  hedonist.  Taken  in  its  crudest 
form,  this  view  maintains  that  our  conduct  is  always  con- 
trolled, directly  or  indirectly,  by  a  regard  for  pleasure  and 
pain  such  that  we  tend  always  to  avoid  the  latter  and  seek 
the  former.  Of  course,  in  facing  the  actual  complexities  of 
human  behavior,  it  has  to  be  recognized  that  we  often 
endure  a  present  pain  for  the  sake  of  a  future  pleasure,  but 


r  -\  |_  U,  R  V" 


FEELING 

««<•«.——  ---- 

only  under  the  conviction  that  the  expected  pleasure  will 
outweigh,  either  in  intensity  or  permanency,  the  momen- 
tary pain. 

It  is  possible  so  to  formulate  this  position  as  to  make  its 
successful  contradiction  decidedly  difficult.  But  human 
nature  is  generally  very  unwilling  to  accept  such  a  descrip- 
tion as  accurate  to  the  facts.  Whether  this  unwillingness 
merely  reflects  a  universal  moral  vanity,  or  whether  it  is 
really  based  upon  a  keener  insight  into  the  actual  facts, 
it  remains  true  that  this  view  has  never  succeeded  in  secur- 
ing any  large  following.  Ethicists  and  psychologists  alike 
have  criticized  it  on  the  ground  that  if  one  is  to  describe 
the  situation  in  terms  of  the  actual  motives  that  are  con- 
sciously present  to  human  beings,  an  explicit  control  by 
considerations  of  pleasure  and  pain  is  relatively  rare.  Cer- 
tainly no  tired  mother,  sitting  up  through  the  long  hours 
of  the  night  with  a  sick  child,  can  for  a  moment  be  sup- 
posed to  have  her  conduct  controlled  by  any  thought  of 
the  pleasure  which  she  is  getting  from  the  act.  Nor  would 
it  be  fair  to  her  actual  mental  processes  to  say  that  she  is 
controlled  by  the  pleasure  which  she  hopes  to  experience 
as  a  result  of  her  care  when  the  child  recovers.  Such  acts 
may  be  called  instinctive,  and  in  part  no  doubt  they  are 
such,  but  they  are  none  the  less  voluntary,  and  so  far  as 
concerns  their  conscious  motive,  pleasure  and  pain  as  such 
are  hardly  ever  in  the  horizon,  except  perhaps  to  be  impa- 
tiently banished. 

Between  the  two  extremes  of  doctrine,  the  one  tending 
to  urge  that  pleasure  and  pain,  if  not  the  sole  motives  in 
voluntary  behavior,  are  at  least  the  dominant  ones,  the 
other  regarding  them  as  of  no  consequence,  is  perhaps  to 
be  found  the  real  truth.  It  would  surely  be  idle  to  main- 


202  AN  INTRODUCTION  TO  PSYCHOLOGY 

tain  that  pleasure  and  pain  play  no  part  in  the  early  stages 
of  our  acquaintance  with  the  physical  world  in  which  we 
live.  That  the  burned  child  dreads  the  fire  has  become  a 
text  for  hundreds  of  sermons  designed  to  exploit  the  moral 
consequences  of  sin.  On  the  other  hand,  the  adage  which 
teaches  that  to  spare  the  rod  is  to  spoil  the  child  postulates 
the  value  of  pain  as  an  element  in  education  of  the  formal 
kind.  The  entire  modern  doctrine  of  interest  as  essential 
in  education  and  the  abundant  experiments  exhibiting  the 
dynamic  effects  upon  children  of  approval  and  other  pleas- 
urable incentives,  imply  a  widespread  conviction  that 
pleasurable  experiences  serve  to  energize  and  motivate 
conduct  in  some  fashion  or  other. 

It  is  of  course  absurd  to  suppose  that  agreeableness  or 
disagreeableness  merely  as  such  are  ever  the  direct  objects 
of  reflective  choice,  when  we  are  deliberating  about  our 
lines  of  conduct.  For  one  thing,  it  is  generally  agreed  by 
psychologists  that  we  have  no  power  thus  to  summon  from 
memory  or  imagination  these  pure  disembodied  affective 
elements.  But  on  the  other  hand,  it  would  be  equally 
untrue  to  the  facts  to  say  that  the  expected  agreeableness 
or  disagreeableness  of  a  line  of  conduct  has  no  weight  what- 
ever in  determining  a  decision.  We  may  not  formulate  the 
decision  to  ourselves  in  terms  that  stress  the  consequences 
in  feeling.  Indeed,  we  may  be  more  or  less  oblivious  at  the 
time  to  such  consequences.  But  so  closely  knit  is  the  fabric 
of  our  entire  thought  process  that  we  could  not  without 
very  special  effort  divorce  from  our  thinking  all  influence 
of  feeling. 

Feeling  and  Voluntary  Action. — It  has  been  a  common 
doctrine  and  is  one  for  which  so  eminent  a  psychologist  as 
Wundt  stands  sponsor,  that  voluntary  actions  always  grow 


FEELING  203 

out  of  feelings,  or,  expressed  otherwise,  that  no  volitional 
act  ever  occurs  except  in  response  to  feeling.  The  par- 
ticular formulation  which  Wundt  offers  connects  acts  of 
will  with  emotion,  out  of  which  he  teaches  that  they  always 
spring.  The  more  familiar  form  of  the  doctrine  implies 
that  choice  is  determined  by  motives  which  in  the  last 
analysis  go  back  to  our  feelings.  Either  of  two  possible 
lines  of  conduct  may  be  perfectly  rational  and  entirely 
defensible,  but  for  the  one  we  feel  a  strong  predilection  and 
toward  the  other  a  powerful  aversion.  Our  choice  rests,  in 
such  a  case,  not  upon  the  sheer  rationality  of  the  act,  but 
upon  our  feeling  regarding  the  alternatives.  While  there 
may  be  decisions  which  are  entirely  cold-blooded  and  intel- 
lectualistic,  and  while  many  of  our  acts  are  essentially 
habitual  and  carried  out  without  any  particular  reflection, 
1here  can  be  no  doubt  that  in  great  ranges  of  our  conduct 
such  a  description  is  correct,  in  that  the  psychologically 
moving  factor  which  determines  us  to  choose  one  rather 
than  another  course  of  action  is  to  be  stated  in  terms  of 
our  subjective  prejudices  and  feelings,  rather  than  in 
terms  of  pure  reason. 


CHAPTER  XII 
EMOTION 

Feeling  and  Emotion. — Most  familiar  of  all  the  forms 
of  feelings  are  the  emotions.  Although  this  term  'emotion' 
is  naturally  somewhat  loosely  used  in  ordinary  parlance, 
it  applies  in  general  to  states  of  mind  marked  by  some 
degree  of  excitement  and  commonly  by  the  noticeable  pres- 
ence of  pleasantness  or  unpleasantness.  Despite  the  fact 
that  these  states  of  excitement  tend  to  shade  off  into  condi- 
tions of  a  relatively  neutral  kind,  so  that  there  is  no  sharp 
line  to  be  drawn  between  emotional  and  non-emotional 
states,  it  is  nevertheless  profitable  to  devote  some  consid- 
eration to  the  more  overt  emotions  which  possess  certain 
definite  peculiarities  tending  to  set  them  off  with  reasonable 
distinctness  from  other  mental  conditions.  Anger,  fear, 
hate,  love,  grief,  embarrassment,  may  serve  to  suggest  the 
more  vivid  and  constant  forms  of  emotion  to  which  we 
shall  now  direct  our  attention.  This  group  Professor 
James  used  to  designate  as  the  coarser  emotions. 

Emotion  and  Instinct. — The  outstanding  mark  which 
characterizes  these  grosser  emotions  is  their  intimate  con- 
nection with  reflex  and  instinctive  modes  of  behavior. 
Some  writers  have  gone  so  far  as  to  say  that  emotion  is 
simply  the  psychological  side  of  an  instinct,  it  is  what  we 
feel  when  we  perform  certain  kinds  of  instinctive  acts. 
William  James  and  the  Danish  psychologist  Lange  have 
given  the  most  extreme  formulations  to  this  view.  They 

204 


EMOTION  205 

differ,  to  be  sure,  in  some  essential  details,  but  the  main 
contention  which  each  makes  is  that  in  an  emotional  experi- 
ence the  characteristic  features  are  contributed  by  changes 
in  our  consciousness  brought  about  through  certain  move- 
ments which  are  made  reflexly  or  instinctively.  To  bring 
the  doctrine  out  in  the  most  dramatic  way,  James  puts  the 
case  by  saying  that  "we  feel  sorry  because  we  cry,  angry 
because  we  strike,  afraid  because  we  tremble." 

The  James-Lange  Theory  of  Emotion. — The  common 
view  of  emotional  expression  has  generally  held  that  the 
clenching  of  the  fist  and  the  distortion  of  the  face  in  anger 
are  the  results  of  the  previously  existing  emotion.  The 
theory  to  which  we  are  now  referring  admits,  of  course,  that 
these  muscular  movements  are  in  a  perfectly  real  sense 
expressions  of  the  emotions,  but  it  maintains  that  if  these 
and  all  the  other  motor  and  glandular  expressions  are 
eliminated  everything  which  is  most  characteristic  of  the 
specific  feeling  of  anger  at  once  disappears.  The  actual 
performance  of  the  experiment  which  this  suggests  is 
obviously  difficult,  because  in  emotions  of  the  violent  kind, 
like  rage  and  anger,  many  of  the  most  important  muscular 
movements,  such  as  those  of  the  heart  and  diaphragm,  are 
not  under  voluntary  control.  Defenders  of  this  doctrine 
maintain  that  one  may  have  an  entirely  lucid  apprehension 
of  a  situation  as  one  justifying  anger,  but  that  the  emotion 
is  only  felt  when  some  or  all  of  the  instinctive  muscular 
movements  are  made.  These  comprise  among  others — in 
the  case  of  anger — violent  tension  of  most  of  the  voluntary 
muscles,  particularly  those  of  the  hands,  arms,  and  chest, 
changes  in  the  tonicity  of  the  blood  vessels,  by  virtue  of 
which  the  face  often  becomes  scarlet,  changes  in  the  power 
and  rate  of  the  heart-beat,  and  profound  alterations  in  the 


206  AN  INTRODUCTION  TO  PSYCHOLOGY 

breathing.  Many  other  consequences  affecting  both  the 
muscular  and  glandular  system .  might  be  mentioned,  but 
these  illustrations  will  suffice. 

Each  of  these  movements  sets  up  sensory  changes,  many 
of  them  accompanied  by  changes  in  the  feeling-tone,  and 
the  sum  total  of  these  disturbances  constitutes  the  pecul- 
iarly emotional  part  of  the  experience.  If  one  looks  at  a 
bear  behind  the  bars  of  its  cage  in  the  zoological  garden, 
the  experience  may  be  wholly  lacking  in  any  particular 
emotional  color.  But  the  same  bear,  inspected  at  the  same 
distance  without  the  intervening  bars,  elicits  a  great  group 
of  these  instinctive  reactions,  which,  fusing  with  the  per- 
ception of  the  animal,  constitute  the  emotion  of  fear. 

The  particular  group  of  motor  reactions  which  are  thus 
called  out  by  emotional  objects  are  native  and  inherited, 
not  acquired.  No  one  has  to  be  taught  how  to  behave  when 
afraid,  when  angry,  when  embarrassed,  or  when  in  the 
power  of  any  of  these  commoner  emotions.  Every  child 
shows  himself  from  the  beginning  a  passed  master  in  the 
expressions  of  anger,  for  example.  These  performances 
are,  therefore,  fairly  to  be  regarded  as  instinctive,  and  it 
is  the  modification  of  our  consciousness  brought  about  by 
these  untaught  and  unlearned  motor  activities,  which  in  the 
view  of  the  James-Lange  doctrine  constitutes  the  essential 
mark  of  emotion.  The  reader  will  readily  infer,  in  the 
light  of  our  previous  analysis  of  memory,  that  individual 
experience  will  tend  to  emphasize  many  of  these  native 
reactions.  The  original  expression  of  fear  or  of  anger  is, 
in  the  nature  of  the  case,  an  entirely  unique  experience; 
but  after  one  has  been  subjected  to  the  emotion  a  number 
of  times,  one  naturally  learns  what  to  expect,  and  the  effect 
of  one's  memories  of  previous  similar  situations  may  enter 


EMOTION  207 

to  give  tone  to  a  situation  which  does  not  itself  call  out 
in  any  complete  way  the  full  catalogue  of  natural  re- 
sponses.1 

No  one  doubts  that  these  grosser  emotions  possess  char- 
acteristic motor  accompaniments  commonly  called  their 
expressions.  The  real  point  under  debate  is,  therefore, 
whether  the  emotional  feeling  is  entirely  prior  to  and  inde- 
pendent of  changes  in  the  field  of  consciousness  occasioned 
by  the  movements,  or  whether  these  changes  so  elicited 
constitute,  as  James  and  Lange  maintain,  the  essence  of 
emotion  as  distinguished  from  non-emotional  states.  The 
racially  hereditary  or  instinctive  nature  of  the  responses  is 
not  in  question. 

Stimuli  to  Emotions. — The  original  emotional  stimulus 
is,  of  course,  sensory,  e.g.,  something  we  see,  or  touch.  But 
it  soon  comes  about,  as  a  result  of  the  development  of 
memory  and  the  ideational  processes,  that  thoughts  call  out 
emotional  reactions  as  vividly  and  as  readily  as  do  sense 
perceptions.  The  thought  of  an  insulting  remark  may  elicit 
quite  as  violent  a  reaction  of  anger  or  shame  as  did  the 
original  experience.  Moreover,  an  emotional  reaction  may 

1  There  has  been  some  disposition  to  attack  the  validity  of  this 
theory  on  the  ground  of  certain  physiological  experiments,  part  of 
which  tend  to  show  an  intimate  inter-relation  between  emotion  of 
the  fear-anger  type  and  certain  glandular  activities,  particularly 
those  of  the  adrenals.  The  other  line  of  criticism  is  based  upon 
experiments  on  dogs,  where  the  brain  was  prevented  by  operation 
from  receiving  incoming  impulses  from  nearly  all  the  viscera  and 
from  the  surfaces  of  the  body  lower  than  the  head  region.  In  this 
case  the  behavior  of  the  animals  seemed  to  suggest  relatively  little 
change  in  the  emotions  named.  This  is  not  the  place  to  enter  upon 
any  attempt  to  consider  these  contributions  in  detail.  It  is  not  the 
view  of  the  writer  that  the  criticisms  are  valid  as  against  the  main 
points  of  the  theory  under  discussion.  See  an  article  by  the  author 
in  the  Psychological  Review,  Vol.  XXIII,  1916,  p.  251. 


208  AN  INTRODUCTION  TO  PSYCHOLOGY 

readily  be  transposed  from  one  sensory  stimulus  to  another, 
as  when  a  child  learns  to  associate  the  sight  of  his  bottle 
with  the  satisfaction  of  his  hunger  and  the  taste  of  the 
milk.  Just  how  far  we  inherit  a  disposition  to  react  in  the 
emotional  way  to  specific  kinds  of  stimuli  is  not  altogether 
clear.1  But  it  is  clear  that  however  various  the  stimulations 
which  produce  emotions,  the  motor  and  glandular  reactions 
are  relatively  fixed.  It  is  sometimes  alleged,  for  example, 
that  babies  are  naturally  afraid  of  darkness  and  of  fur. 
Neither  of  these  reactions  seems  to  be  at  all  universal,  but 
there  is  some  evidence  to  indicate  that  one  or  both  are 
represented  in  the  case  of  certain  children.  Certain  it  is 
that  when  a  stimulus  is  encountered  that  calls  forth  fear, 
the  child's  response  is  of  the  instinctive  and  fairly  stereo- 
typed form. 

Organic  Changes  in  Emotion. — Dr.  Cannon  and  others 
have  shown  that  in  violent  emotions  like  fear  and  anger, 
certain  important  substances  are  thrown  into  the  blood 
stream  by  the  ductless  glands  of  the  body.  Adrenalin,  the 
secretion  of  the  adrenal  gland,  affords  a  striking  illustra- 
tion of  this  fact.  This  substance  markedly  diminishes  the 
effects  of  fatigue  in  the  muscles,  makes  the  blood  coagulate 
more  rapidly  and  in  general  adapts  the  organism  to  put 
forth  its  maximal  efforts.  Similarly,  an  increased  amount 
of  sugar  is  secreted  by  the  liver,  thus  furnishing  the  or- 
ganism more  fuel  than  usual.  These  discoveries  all  indicate 
that  in  emotion  the  organism  enters  upon  a  condition  of 

1  Watson  in  an  unpublished  paper  has  tentatively  reported  three 
primitive  emotional  reactions  and  their  stimuli  as  follows:  (1) 
anger — stimulus — any  constriction  of  free  movement;  (2)  fear — 
stimulus — removal  of  bodily  support,  possibly  loud  sounds;  (3)  af- 
fectionate feeling — stimulus — gentle  stroking  or  tickling. 


EMOTION  209 

excitability  notably  different  from  the  normal  state.  Some 
of  our  "behaviorists"  look  forward  to  the  day  when  we 
can  classify  the  different  emotions  in  terms  of  the  glandular 
products  thus  introduced  into  the  blood.  Whether  this 
result  be  attained  or  not,  the  facts  already  in  hand  exhibit 
the  remarkable  degree  to  which  emotions  are  bound  up 
with  organic  reflexes  both  of  gland  and  muscle. 

Ideational  Element  in  Emotion. — In  emphasizing  the 
instinctive  and  the  motor  aspects  of  emotion,  it  must  not 
be  understood  that  we  intend  in  any  way  to  overlook  the 
ideational  parts  of  the  process.  These  are  of  the  utmost 
moment,  and  they  become  increasingly  so  as  mental  life 
evolves.  Mental  disease  apart,  one  does  not  have  undi- 
rected fear  in  general,  impersonal  anger  or  embarrassment 
in  general.  One  is  afraid  of  a  particular  object  or  situa- 
tion, one  is  angry  at  a  special  individual  or  group,  one  is 
embarrassed  by  a  particular  situation.  In  all  these  in- 
stances one's  intellectual  apprehension  of  the  circum- 
stances, together  with  the  various  thoughts  suggested  in 
each  instance,  enter  to  determine  the  sum  total  of  the  emo- 
tional state.  Even  in  the  simplest  instances  this  intellectual 
appreciation  is  momentous.  To  revert  to  an  earlier  illus- 
tration: the  bear,  which  is  an  object  of  amused  interest  in 
the  one  case,  an  object  of  horrified  fear  in  the  other,  may 
be,  as  a  sheer  matter  of  visual  sensation,  one  and  the  same. 
Only  when  he  is  apprehended  as  a  potential  source  of 
great  bodily  suffering  does  he  become  an  emotional  stimulus 
to  fear. 

The  intellectual  element  in  emotion  tends  to  become  more 
conspicuous  as  we  pass  from  the  coarser  to  the  finer  forms 
of  emotional  experience.  In  the  range  of  aesthetic  appre- 
ciation, for  example,  there  is  likely  to  be  distinctly  less 


210  AN  INTRODUCTION  TO  PSYCHOLOGY 

evidence  of  a  purely  bodily  resonance,  with  relatively  more 
of  the  subtle  forms  of  intellectual  pleasure.  At  no  point, 
however,  where  we  can  properly  speak  of  emotion,  is  this 
cognitive  element  wholly  lacking.  Emotion  is  therefore  a 
highly  complex  condition  in  which  sensations,  ideas,  and 
affections  are  intricately  combined. 

Emotion  a  Phenomenon  of  Interrupted  Mental 
Activity. — The  intensity  of  emotional  experiences,  as  con- 
trasted with  other  experiences,  may  perhaps  be  connected 
with  the  fact  of  interruption  to  on-going  processes.  Pro- 
fessor Dewey  has  defended  the  thesis  that  emotions  are 
primarily  called  out  when  two  instinctive  tendencies  are  in 
competition  for  expression.  Whatever  judgment  may  be 
passed  upon  this  particular  view,  there  can  be  no  doubt 
that  all  the  more  violent  emotions  are  incidents  of  vigorous 
interruption  to  the  ordinary  flow  of  mental  life.  The 
stimulus  which  calls  forth  anger  is  typically  one  which 
blocks  or  thwarts  our  momentary  activity.  The  same  thing 
may  be  said  of  fear,  and  in  general  the  onset  of  an  emotion 
is  marked  by  the  invasion  and  dislocation  of  whatever 
processes  are  at  the  moment  going  on.  In  the  joyful  emo- 
tions this  momentary  interruption  may  be  succeeded  by  a 
torrential  flow  of  delicious  excitement. 

Darwin's  View  of  Emotion. — In  connection  with  the 
general  view  of  emotion  which  we  have  presented,  it  may 
be  of  interest  to  mention  briefly  certain  theories  of  Charles 
Darwin  about  the  origin  of  our  emotional  responses.  The 
reader  will,  of  course,  bear  in  mind  the  fact  that  as  a  rule 
Darwin's  views  rest  on  the  doctrine  that  bodily  structures, 
as  well  as  the  forms  of  behavior,  represent  the  survivals 
of  the  fittest  in  the  struggle  for  existence  of  millions  of 
generations  of  ancestors.  This  conception  naturally  raises 


EMOTION  211 

i 
the  question  as  to  the  utility  of  our  present  equipment  of 

instinctive  reactions,  some  of  which,  like  trembling  when 
upon  a  high  place,  seem  peculiarly  inept  and  disadvan- 
tageous. Without  going  into  complete  details,  one  or  two 
of  the  Darwinian  views  may  be  mentioned. 

There  is  first  the  contention  that  many  of  the  forms  of 
reaction  now  encountered  were  useful  at  a  previous  period 
of  racial  history.  The  stock  illustration  of  this  sort  of 
thing  is  the  elevation  of  the  upper  lip  in  scorn  or  in  anger, 
a  performance  which  has  now  no  particular  utility,  but 
which  in  social  conditions  of  a  franker  and  less  restrained 
character  obviously  may  have  been  highly  useful.  A  second 
doctrine  involves  the  so-called  principle  of  'antithesis.' 
The  savage  attitudes  of  an  angry  dog  obviously  have  a  cer- 
tain utility.  Over  against  these,  as  the  expression  of 
affectionate  moods,  are  an  exactly  opposite  group.  The 
theory  here  implies  not  so  much  the  utility  of  the  second 
group,  as  its  appearance  because  it  represents  most  nearly 
a  complete  set  of  muscular  opposites  to  the  contrasting  emo- 
tioual  state.  It  cannot  be  said  that  the  Darwinian  explana- 
tions have  at  all  completely  solved  the  riddle  of  certain  of 
our  emotional  reactions,  but  they  will  at  least  serve  to  sug- 
gest the  lines  along  which  it  may  perhaps  be  found  finally 
possible  to  render  intelligible  some  of  the  responses  which 
now  perplex  us. 

Classification  of  Emotions. — Many  classifications  of 
emotion  have  been  suggested,  but  none  has  succeeded  in 
winning  permanent  general  favor.  That  which  seems  on 
the  whole  most  fundamental  involves  a  division  into  those 
which  are  historicall^--primary,  and  those  which  are 
derived  or  secondary.  Were  we  in  a  position  to  apply  this 
principle  of  classification  confidently,  it  would  presumably 


212  AN  INTRODUCTION  TO  PSYCHOLOGY 

satisfy  all  essential  needs.  We  are,  however,  obliged  to 
use  it  subject  to  appreciable  uncertainty  regarding  the 
dividing  line  which  it  attempts  to  employ. 

It  seems  safe  to  regard  such  emotions  as  anger  (offensive) 
and  fear  (defensive)  as  unequivocally  primary.  Pre- 
sumably there  should  be  also  recognized  something  cor- 
responding to  love  or  affection  in  a  broad,  general  sense. 
Superposed  upon  these  foundations  are  such  emotions  as 
gratitude,  sympathy  in  many  of  its  forms,  remorse,  and 
pity.  Each  of  these  last-named  experiences  has  obvious 
elements  of  instinct  in  it,  and  with  the  possible  exception 
of  remorse,  each  of  them  finds  some  representation  in  ani- 
mal behavior.  But  as  contrasted  with  the  members  of  the 
first  group  it  is  fairly  clear  that  they  depend  for  their 
content  upon  elements  which  obviously  grow  out  of  experi- 
ence. They  are  therefore  in  a  reasonable  sense  to  be 
regarded  as  secondary  and  to  some  extent  derived.  Pre- 
sumably they  involve  one  or  another  of  the  elements  of  the 
primary  group. 

Mood,  Temperament,  Sentiment. — Side  by  side  with 
emotion  we  must  put  the  facts  of  sentiment,  mood,  and 
temperament,  for  they  are  all  inter-related  phenomena. 

The  term  emotion  is  usually  applied  to  a  relatively  brief 
experience  whose  beginning  and  end  can  be  fairly  marked 
off.  Mood  is  a  term  which  we  apply  to  a  comparatively 
permanent  emotional  condition.  One  may  thus  be  cheerful 
throughout  a  considerable  period  of  time.  This  means  that 
while  such  a  mood  endures,  one  is  susceptible  chiefly  to 
those  emotions  which  are  closely  related  to  the  mood. 

The  term  temperament  is  somewhat  loosely  used  to  apply 
to  still  more  enduring  emotional  dispositions,  but  with 
some  reference  also  to  intellectual  habits  and  motor  traits. 


EMOTION  213 

The  familiar  division  of  temperaments  into  sanguine, 
choleric,  melancholic,  and  phlegmatic  has  no  very  funda- 
mental psychological  basis,  but  serves  roughly  to  charac- 
terize certain  gross  differences  in  individual  make-up. 
"The  sanguine  and  choleric  types  are  alert  and  easily 
stirred,  the  latter  displaying  a  more  intense,  the  former  a 
feebler,  interest.  The  melancholic  and  phlegmatic  types 
are  slow  in  response,  the  former  evincing  a  strong  and 
vivid  interest  when  once  aroused,  the  latter  manifesting 
a  persistent  but  weak  interest. ' '  It  will  naturally  be  under- 
stood that  there  are  considerable  variations  in  individuals, 
even  when  they  conform  roughly  to  these  general  lines  of 
distinction.  Moreover,  there  are  all  kinds  of  individual 
differences  in  intellectual  equipment,  affecting  memory, 
imagination,  attention,  etc.,  which  must  be  recognized  in 
any  general  estimate  of  temperamental  peculiarities. 

While  we  commonly  think  of  disposition  as  being  depend- 
ent upon  the  prevalent  emotional  attitude,  so  that  one  is 
likely  to  be  good-natured  who  temperamentally  responds 
to  most  situations  with  emotions  of  the  buoyant  and  more 
or  less  humorous  type,  it  is  equally  true  that  emotions  are 
likely  to  be  affected  by  dominant  trains  of  thought.  At 
this  point  what  we  call  sentiment,  i.e.,  a  relatively  per- 
manent disposition  or  attitude,  is  of  prime  consequence. 
Persons  whose  thinking  tends  to  dwell  upon  abstract  and 
theoretical  subjects  are  likely  to  be  lacking  in  sensitiveness 
to  social  and  personal  situations.  They  may  be  of  an 
entirely  kindly  character  when  such  matters  are  brought 
forcefully  to  their  notice,  but  they  are  not  naturally  alert 
to  their  appeal.  On  the  other  hand,  persons  whose  thought 
tends  to  dwell  upon  the  persistent  underlying  problems  of 
social  organization  are  apt  to  be  emotionally  responsive  to 


214  AN  INTRODUCTION  TO  PSYCHOLOGY 

human  distress.  When  we  designate  particular  individuals 
as  sentimental,  we  mean  to  imply  an  exaggeration  of  this 
permanent  emotional  mood  in  one  direction  or  another. 
There  is  an  essentially  reciprocal  relation  between  senti- 
ments and  emotions,  for  the  cultivation  of  any  set  of  emo- 
tions tends  to  foster  a  prevalent  sentiment  favorable  to 
such  emotions,  whereas  conversely  and  obviously,  a  senti- 
ment is  itself  an  invitation  to  the  corresponding  emotion. 
Emotion  and  Volition. — Whatever  view  we  entertain 
regarding  the  relation  of  feeling  to  volition — a  matter  dis- 
cussed in  the  previous  chapter — we  must  recognize  that  our 
emotional  life  sustains  a  most  important  relation  to  our 
conduct  and  character.  A  well-balanced,  forceful  character 
implies  strong  normal  emotions,  responding  without  exag- 
geration to  the  demand  of  human  relations.  The  wholly 
unemotional  person  may  meet  the  requirements  of  some 
occasional  crises  with  great  distinction,  but  in  general  he 
is  likely  to  be  a  cold-blooded,  unsympathetic  individual, 
oblivious  to  many  of  the  finer  things  in  life.  On  the  other 
hand  some  persons  suggest  by  their  behavior  an  active  emo- 
tional volcano  and  from  such  we  can  hardly  look  for  well- 
poised  opinions  or  consistent  and  efficient  conduct.  We 
shall  discuss  more  fully  in  a  later  chapter  the  relation  of 
the  will  to  instinct  and  emotion. 


CHAPTER  XIII 
INSTINCT 

Our  analysis  of  emotion,  leading  us  as  it  did  into  the 
region  of  instinct,  carries  us  back  to  matters  which  we 
touched  upon  at  the  very  beginning  of  our  study.  We 
must  now  look  somewhat  more  closely  into  this  part  of  our 
human  equipment. 

The  Nature  of  Instinct. — Without  making  any  pre- 
tense of  precision  in  definition,  it  may  be  said  at  once 
that  instincts,  like  reflex  acts,  rest  upon  the  presence  in 
the  nervous  system  (both  central  and  autonomic)  of 
native  pathways  for  the  discharge  of  impulses  into  the 
muscles.  Some  of  the  instincts  are  perfect  at  birth. 
In  all  young  mammals  the  instinct  of  sucking  is  of  this 
character.  Others  appear  and  come  to  perfection  at 
later  stages  of  the  animal's  life.  But  whenever  they 
appear,  they  involve  innate,  inherited  forms  of  conduct  and 
are  in  no  sense  learned  or  acquired  like  the  voluntary  forms 
of  action.  In  general,  they  are  to  be  differentiated  from 
reflex  acts  in  part  by  their  complexity,  the  reflex  involving 
generally  a  simple  muscular  response  to  a  single  stimulus, 
and  in  part  by  their  being  ordinarily  conscious,  whereas 
many  reflexes  are  unconscious.  After  all,  however,  the  dif- 
ferences are  perhaps  not  so  important  as  the  similarities, 
and  certain  it  is  that  the  one  passes  over  into  the  other 
through  stages  which  are  not  separated  by  any  sharp 
boundaries. 

215 


216     AN  INTRODUCTION  TO  PSYCHOLOGY 

These  instinctive  and  reflex  activities  serve  to  give  the 
organism  capacity  to  meet  many  of  the  more  important 
situations  to  which  it  must  adjust,  and  in  certain  of  the 
lower  animals  they  comprise  substantially  the  sum  total  of 
its  abilities.  In  the  human  being  they  form  the  foundation 
upon  which  is  built  all  that  individualistic  adjustment  rep- 
resented by  his  personal  experience.  Not  only  does  the 
human  child  begin  his  life  career  with  a  capital  made  up 
solely  of  these  hereditary  achievements;  they  remain 
throughout  his  life  as  dominating  factors  from  which  he 
derives  the  larger  part  of  his  more  enduring  motives.  Our 
analysis  of  emotion  will  have  naturally  led  the  reader  to 
anticipate  that  in  discussing  instinct  we  must  repeat  to  some 
extent  points  which  we  have  considered  already.  For  we 
have  insisted  that  our  emotions  are  knit  up  in  the  most 
intimate  way  with  our  instincts. 

As  we  pointed  out  in  the  preceding  chapter,  there  are 
many  possible  classifications  of  emotions  and  instincts. 
For  example,  they  have  been  grouped  as  social,  or  personal, 
as  egoistic  or-  altruistic,  as  defensive  or  aggressive.  At 
present  the  commonest  grouping  is  probably  that  which 
attempts  to  bring  together  instincts  which  are  primary  and 
relatively  simple  as  over  against  those  which  are  secondary, 
derived,  and  complex.  All  the  divisions  must  be  regarded 
as  merely  rough  attempts  to  classify  phenomena  of  which 
our  knowledge  is  as  yet  too  imperfect  to  warrant  dogmatic 
assertions.  Before  entering  upon  this  rough  practical 
grouping,  it  may  perhaps  clarify  the  reader's  view  of  the 
situation  to  point  out  certain  peculiarities,  of  human 
instincts  as  compared  with  those  of  the  animals. 

Comparison  of  Human  and  Animal  Instinct. — It  is 
commonly  supposed  that  the  higher  animals  possess 


INSTINCT  217 

appreciably  more  instincts  than  does  man.  Professor 
James  and  others  maintain,  however,  that  a  contrary  state- 
ment is  nearer  the  truth.  Undoubtedly  animals  have  more 
highly  perfected  instincts  than  any  which  we  find  in  man. 
Certainly  neither  the  child  nor  the  adult  displays  any  such 
remarkably  elaborate  instinct  as  that  shown  by  the  young 
spider  in  the  construction  of  its  first  intricate  web.  On  the 
other  hand,  it  seems  to  be  the  fact  that  men  have  more 
rudimentary  impulses  of  an  essentially  instinctive  kind 
than  any  animal. 

Neither  in  man  nor  in  the  animals,  however,  are  instincts 
so  blind  nor  so  invariable  in  their  operation  as  is  sometimes 
supposed.  Even  reflex  acts  are  some  of  them  susceptible  to 
appreciable  alteration,  and  practically  all  exhibit  marked 
variation  from  one  individual  to  another.  In  the  higher 
animals,  many  an  instinct  may  be  stamped  out  and  disap- 
pear, either  because  opportunity  for  its  development  is  lack- 
ing at  the  appropriate  time,  or  because  its  first  expression 
is  followed  by  painful  consequences.  The  disposition  of 
the  young  chick  to  follow  moving  objects  is  one  which 
passes  away  with  some  promptness  if  it  be  not  cultivated. 
Commonly  the  maternal  hen  offers  such  an  object  and  the 
chick's  instinct  is  forthwith  developed  into  a  habit  which 
may  last  indefinitely.  Any  of  the  less  fundamental  in- 
stincts may  be  temporarily,  or  even  permanently,  inhibited 
by  painful  experiences.  The  chick,  again,  has  a  strong 
tendency  to  peck  at  small  objects.  If  those  supplied  be 
given  a  strongly  disagreeable  taste  or  be  coated  with 
some  burning  acid  substance,  the  instinct  may  be  gravely 
disarranged. 

The  plasticity  of  human  instinct  is  much  more  familiar. 
Indeed,  because  of  its  variability  there  is  little  appreciation 


218  AN  INTRODUCTION  TO  PSYCHOLOGY 

of  the  really  instinctive  character  of  many  forms  of  human 
conduct.  The  reactions  to  circumstances  which  cause 
embarrassment  are  essentially  of  the  instinctive  kind,  and 
yet  they  may  vary  widely  in  different  individuals  and  in 
the  same  individual  at  different  times.  The  common  expres- 
sion of  marked  embarrassment  is  blushing.  Some  people, 
however,  rarely  or  never  blush,  but  are  rendered  dumb  by 
embarrassing  situations.  Others  express  their  distress  by 
awkward  movements  of  hands  or  face.  Still  others  are 
overwhelmed  with  a  rush  of  words,  which  in  children  and 
adolescents  often  tend  to  ill-mannered  and  rude  expres- 
sions. One  of  these  reactions  may  be  made  today,  and 
another  one  tomorrow.  This  is  simply  to  say  that  the 
instinct  is  of  a  very  general  and  ill-organized  type.  As 
compared  with  the  animals,  probably  all  human  instincts 
are  decidedly. more  variable,  and  the  reader  can  no  doubt 
summon  from  his  own  observations  abundant  confirmation 
of  this  statement.  Notoriously,  some  individuals  flush 
when  angry,  others  grow  pale.  Some  persons  become 
speechless  when  frightened,  others  tend  to  babble  on  like 
Tennyson's  brook. 

Human  Instincts. — Let  us  return  now  to  the  attempt  to 
make  a  rough  list  of  the  more  important  human  instincts, 
and  to  suggest  a  working  grouping.  Professor  James  gives 
the  following  list:  vocalization,  imitation,  emulation  or 
rivalry,  pugnacity,  anger,  resentment,  sympathy,  fear, 
acquisitiveness,  constructiveness,  play,  curiosity,  sociability 
and  shyness,  secretiveness,  cleanliness,  modesty,  shame,  love, 
jealousy,  parental  love,  and  hunting.  MacDougall  recog- 
nizes instincts  to  flight,  repulsion,  curiosity,  pugnacity,  self- 
abasement,  self-assertion,  and  the  parental  instinct.  From 
the  latter  he  evolves  sympathy  and  indirectly  moral  indig- 


INSTINCT  219 

nation.  He  regards  as  minor  instincts  those  leading  to 
gregarious  habits,  to  reproduction,  and  to  construction. 
Watson,  in  his  recent  study  of  behavior,  lists  locomotion, 
the  obtaining  of  food  and  shelter,  rest,  play,  sleep,  as  the 
foundation  of  daily  life.  Instincts  of  sex,  of  defense  and 
attack,  migration,  mimicry,  and  vocalization  belong  to  less 
sharply  marked  groups. 

Ribot  distinguishes  certain  primitive  tendencies,  of 
which  the  more  purely  physiological  have  to  do  with  the 
maintenance  of  the  body.  The  others,  of  a  more  definitely 
psychological  character,  are  related  to  distinctly  social  and 
racial  situations.  He  speaks  thus  of  the  instinct  of  con- 
servation under  its  defensive  form  as  involving  fear  and 
all  its  modifications.  Under  its  aggressive  form  this  con- 
servative instinct  appears  as  anger,  with  its  various  deriva- 
tives. These  are  properly  the  primary  group,  upon  which 
are  built  the  more  complex  tendencies,  finding  their  most 
definite  expression  in  sympathy  and  the  so-called  tender 
emotions  in  general,  such  as  pity,  and  the  various  forms  of 
non-sexual  personal  affection.  On  the  foundation  repre- 
sented by  these  three  fundamental  groups  he  would  base 
all  the  other  instinctive  and  emotional  traits.  Some,  like 
the  sex  instincts,  appear  relatively  late  and  are  then  com- 
plicated not  only  with  the  instincts  which  appear  earlier, 
but  also  with  the  general  fruits  of  experience.  Still 
another  grouping  which  Pillsbury  has  recently  accepted 
recognizes  (a)  "those  instincts  which  preserve  the  life  and 
provide  for  the  welfare  of  the  individual;  (b)  those  which 
provide  for  the  continuance  of  the  race  and  for  the  family, 
and  (c)  those  which  make  for  the  welfare  of  the  tribe  or 
of  the  social  unit."  Evidently  some  of  the  instincts  will 
overlap  two  or  even  three  of  the  groups. 


220  AN  INTRODUCTION  TO  PSYCHOLOGY 

As  has  been  suggested,  the  -value  of  any  of  these  proposed 
classifications  is  really  dependent  upon  the  particular  inter- 
est or  purpose  which  it  is  designed  to  meet.  If  one  wishes 
to  uncover  the  distinctly  genetic  phases  of  instinct,  then  a 
classification  like  that  of  Ribot  or  MacDougall,  if  it  can 
be  satisfactorily  carried  out,  would  be  best.  If  one  desires 
to  throw  into  the  foreground  those  considerations  which 
pertain  most  distinctly  to  the  evolution  of  society  and  its 
relation  to  the  individual,  then  such  a  grouping  as  was 
mentioned  last  is  likely  to  be  most  convenient.  There  is 
an  added  advantage  in  this  type  of  classification  in  that 
it  lends  itself  rather  readily  to  use  in  connection  with  the 
modern  c /olutionary  conceptions  of  mind. 

Man  has  undoubtedly  developed,  like  other  living 
creatures,  out  of  simpler  antecedent  forms.  In  the  process 
of  evolution  his  mental  as  well  as  his  physical  organization 
has  been  developed  in  response  to  influences  which  are 
partly  physiological  and  partly  social.  Presumably  in  the 
life  of  the  race,  as  in  the  life  of  the  individual,  the  earliest 
exigencies  are  those  which  relate  to  food,  rest,  and  protec- 
tion from  the  assaults  of  climate  and  animal  enemies.  The 
instinctive  equipment  to  meet  these  demands  is  represented 
in  hunger,  thirst,  and  the  anger-fear  reactions.  Superposed 
upon  the  successful  adjustment  to  demands  of  this  char- 
acter is  the  group  of  situations  calling  for  effective  social 
relations  and  leading  speedily  into  the  group  centering  first 
in  the  family  and  then  in  the  tribe  or  social  unit,  whatever 
that  may  be.  At  one  point  or  another  in  this  series  will 
be  found  the  justification  for  each  of  the  instincts  which 
we  have  noted,  the  sum  total  representing  a  rude  balance 
between  those  impulses  which  tend  to  foster  on  the  one  hand 
the  purely  personal  interests  of  the  individual,  and  on  the 


INSTINCT  221 

other  those  of  the  social  group  to  which  he  belongs.  As 
we  shall  see  in  a  later  chapter,  the  great  function  of  volun- 
tary action  is  to  introduce  a  rational  organization  of  these 
raw  instinctive  tendencies;  but,  even  apart  from  rational 
control,  on  evolutionary  grounds  there  must  obviously 
always  be  an  approximate  balance  between  those  instincts 
which  tend  to  exploit  the  individual  at  the  cost  of  society 
and  those  whose  tendency  is  in  the  opposite  direction.  The 
social  group  is  helpless  without  the  individual,  and  the 
individual  cannot  really  come  to  his  own  without  the 
group. 

Theories  of  the  Origin  of  Instinct. — It  will  throw  some 
light  upon  the  general  problem  of  instinct  to  survey  for  a 
moment  certain  of  the  more  important  theories  regarding 
its  origin.  .  Of  these  we  may  mention  three.  At  the  present 
moment  the  one  which  we  shall  first  describe  probably 
enjoys  the  largest  following. 

(1)  The  reflex  theory,  which  is  perhaps  most  often  in 
English  connected  with  the  name  of  Herbert  Spencer,  con- 
ceives instinct  as  built  up  out  of  the  accidental  conjunction 
of  reflex  acts  in  forms  which  are  sufficiently  useful  so  that 
the  animals  possessing  them  are  at  an  advantage  in  the 
struggle  for  existence,  and  thus  tend  to  survive  when  their 
less  fortunate  companions  disappear.  On  the  basis  of  this 
view,  intelligence  plays  no  necessary  part  in  the  original 
establishment  of  the  instinct ;  indeed,  the  doctrine  provides 
for  the  possibility  that  many  of  the  lower  animal  forms 
may  be  very  meagerly  supplied  with  mental  powers. 

This  view  has  to  attribute  the  establishment  of  instincts 
essentially  to  accident,  and  it  necessarily  carries  with  it 
the  further  assumption  that  many  of  these  accidents  turn 
out  unsuccessfully,  so  that  neither  they  nor  the  animals 


222  AN  INTRODUCTION  TO  PSYCHOLOGY 

thus  endowed  survive.  Inasmuch  as  accidental  varia- 
tions are  well  known  to  occur  both  in  the  structure  and  in 
the  behavior  of  animal  forms,  this  difficulty  is  perhaps  not 
very  grave.  A  more  serious  one  concerns  the  fact  that 
some  instincts  are  extremely  elaborate  and  consist  of  a 
series  of  relatively  complicated  acts,  any  one  of  which, 
taken  alone,  may  be  relatively  useless. 

If  the  preservative  value  of  instincts  is  adopted  to  explain 
their  existence,  one  is  then  apparently  obliged  to  assume 
that  the  entire  series  of  steps  in  a  complex  instinct  sprang 
into  existence  at  once  (for  any  single  step  taken  alone  may 
be  useless),  and  this  seems  highly  improbable.  In  any 
event  it  strains  one's  credulity.  The  instincts  in  accord- 
ance with  which  wasps  and  bees  construct  their  nests  and 
lay  up  food  supplies  may  reasonably  be  cited  as  instances 
of  the  type  of  difficulty  mentioned. 

(2)  The  next  theory  is  that  of  lapsed  intelligence. 
Among  psychologists  Wundt  is  probably  the  most  con- 
spicuous adherent  of  this  view.  It  assumes  that  instincts 
arise  out  of  acts  originally  intelligent  and  voluntary  in 
character,  that  certain  of  these  acts,  being  extremely  useful 
and  being  oft  repeated,  get  themselves  established  as  firmly 
ingrained  habits.  These  habits  are  then  transmitted  to 
offspring  and  so  appear  in  the  younger  generations  as 
innate. 

Evidently  this  theory  involves  two  fundamental  assump- 
tions without  which  it  can  hardly  be  made  plausible  at  all. 
The  one  is  that  intelligence  of  the  kind  expressed  in  volun- 
tary action  is  an  attribute  of  the  lowest  animal  forms.  The 
other  is  that  acquired  habits  may  gradually  become  so 
well  established  that  they  are  transmitted  by  heredity. 
Both  these  assumptions  are  vigorously  challenged  by  scien- 


INSTINCT  223 

tists  of  repute.  The  second  in  particular  has  been  sub- 
jected to  very  severe  arraignment  by  the  great  group 
of  biologists  who  doubt  or  disbelieve  that  any  character- 
istics acquired  by  an  individual  in  his  own  lifetime  are 
ever  passed  on  by  heredity  to  his  offspring.  The  matter  is 
still  under  active  discussion  and  experiment  at  the  hands 
of  zoologists,  and  we  shall  have  to  await  their  final  verdict. 
Meantime,  the  theory  of  lapsed  intelligence  probably 
enrolls  a  much  smaller  number  of  defenders  than  the  reflex 
theory.  It  has  one  great  advantage  over  the  latter  theory 
in  that  it  is  in  a  position  to  explain  the  slow  building  up 
of  complex  instincts,  because  it  can  make  use  of  the  selec- 
tive influence  of  intelligence  in  picking  out  groups  of  useful 
coordinations. 

(3)  The  theory  of  organic  selection  is  represented  among 
psychologists  by  Professor  J.  M.  Baldwin.  It  maintains 
that  consciousness  is  probably  present  and  significant  even 
in  the  very  low  organisms,  and  it  may  be  assumed  to  be 
of  value  in  just  the  same  way  that  it  is  in  human  beings, 
i.e.,  by  aiding  in  the  adjustments  which  the  organism  makes 
in  its  attempt  to  accommodate 'its  life  to  the  exigencies  of 
its  surroundings.  By  the  assistance  of  these  rudimentary 
forms  of  intelligence,  organisms  may,  in  the  view  of  this 
theory,  be  kept  alive  during  the  period  when  instincts  are 
being  slowly  and  more  or  less  accidentally  built  up.  Indeed, 
intelligence  may  conceivably  exercise  some  influence  in  the 
selection  or  elimination  of  certain  phases  of  the  plastic 
developing  instincts.  The  theory  makes  no  demand,  how- 
ever, for  assent  to  the  doctrine  of  the  transfer  of  acquired 
characteristics.  It  rather  aligns  itself  in  this  matter  with 
the  reflex  theory,  urging  that  only  spontaneous  variations 
are  ever  preserved  and  transmitted  by  heredity.  But  it 


224  AN  INTRODUCTION  TO  PSYCHOLOGY 

obviously  differs  from  the  reflex  theory  in  recognizing  the 
possible  presence  of  intelligence  even  in  low  forms  of 
animal  life,  and  in  assigning  such  intelligence  an  active  and 
indispensable  part  in  keeping  the  species  alive  during  the 
period  when  useful  instincts  are  getting  themselves  estab- 
lished. 

According  to  the  last  two  of  these  theories  intelligence 
is  developed  in  parallel  with  the  instincts.  On  the  basis  of 
the  first  theory,  we  must  look  for  the  appearance  of  intel- 
ligence at  a  relatively  late  point  in  animal  evolution. 
Clearly  if  we  turn  to  the  life  history  of  the  human  indi- 
vidual, we  find  from  the  beginning  unmistakable  evidences 
of  reflex  and  instinctive  acts,  and  although  we  do  not  find 
any  developed  capacities  of  voluntary  control,  we  do  find 
consciousness  present,  and  we  encounter  at  a  very  early 
stage  the  outcropping  of  definitely  volitional  processes.  In 
the  normal  child  the  act  of  nursing  will  occur  almost  imme- 
diately after  birth ;  but  if  the  child  for  any  reason  dislikes 
the  taste  of  the  food  supplied  it,  there  may  be  also  overt 
and  violent  refusal  to  accept  it.  There  are  many  evidences, 
as  was  remarked  earlier  in  the  chapter,  that  instincts  may 
be  definitely  modified  and  controlled  by  voluntary  action. 
So  far  as  concerns  ourselves,  then,  we  can  only  admit  that 
while  instincts  and  reflexes  are  dominant  in  the  primary 
stages  of  our  life  history,  intelligent  control  comes  in  at 
an  early  age  to  modify  these  inherited  forms  of  behavior. 
That  children  ever  inherit  the  acquired  habits  of  their 
parents  has  never  been  proved,  and  is  by  most  competent 
observers  believed  not  to  be  the  fact. 

Instinct  and  Intelligence. — In  the  general  process  of 
evolution  any  particular  generation  necessarily  carries  over 
from  ancestral  conditions  some  instinctive  forms  of  be- 


INSTINCT  225 

havior  which  are  either  partly  or  entirely  useless  under 
extant  circumstances.  It  is,  indeed,  probable  that  some  of 
them  are  at  times  positively  harmful.  Clearly,  such  in- 
stincts are  only  likely  wholly  to  disappear  when  they 
become  so  pernicious  as  to  threaten  the  life  of  the  species 
manifesting  them.  On  the  other  hand,  we  know  that  disused 
organs  tend  to  atrophy,  and  in  the  measure  in  which  con- 
temporary conditions  fail  to  call  out  particular  modes  of 
instinctive  behavior,  there  is  always  a  chance  that  they  may 
gradually  disappear.  Undoubtedly  the  broad  general  func- 
tion of  instincts  is  that  already  many  times  indicated,  to- 
wit,  the  adaptation  of  the  organism  to  the  crucial  features 
of  its  environment  in  advance  of  its  individual  experience. 
As  soon  as  knowledge  begins  to  arise  about  the  effects  of 
the  objects  in  the  environment  upon  the  organism,  intelli- 
gence can  begin  to  act  and  voluntary  control  may  come  in 
to  supplement  or  displace  the  unaided  guidance  of  instinct. 
Many  human  instincts  are  still  of  the  utmost  value,  not 
only  because  of  the  direct  service  which  they  render  in 
advance  of  experience,  but  also  because  they  furnish  per- 
sistent and  powerful  motives  to  lines  of  conduct  which  are 
both  individually  and  racially  indispensable.  The  instinc- 
tive love  of  the  mother  for  the  child,  the  instinctive  sym- 
pathy with  many  forms  of  suffering,  the  instinctive  interest 
in  acquisition,  to  mention  only  these  traits  is  to  name  a 
group  of  instinctive  tendencies  whose  removal  would 
radically  alter  the  whole  texture  of  our  social  fabric. 


CHAPTER  XIV 
ELEMENTS  OF  VOLUNTARY  ACTION 

We  are  now  prepared  to  attempt  what  is  essentially  a 
synthesis  of  all  the  preceding  analyses  and  descriptions  of 
mental  operations.  The  prime  purpose  of  all  sensations, 
acts  of  memory,  imaginings,  reasonings,  and  feelings  is  to 
enable  us  intelligently  to  control  our  conduct.  This  power 
of  intelligent  control  is  in  common  parlance  generally  called 
will.  It  is  not  the  view  of  the  present  writer  that  the  mind 
has  any  special  faculty  properly  to  be  designated  'will.' 
Rather  is  this  term  to  be  understood  as  applicable  to  the 
entire  mind  when  considered  as  an  active  directive  force. 
To  think  is  in  a  very  true  sense  to  will.  To  recall  pur- 
posely is  to  will.  To  sign  one's  name  intentionally  is  to 
will.  In  a  way,  then,  we  have  already  analyzed  and 
described  many  phases  of  our  volitional  processes,  but  it  is 
of  distinct  practical  advantage  to  consider  a  special  group 
of  problems  that  still  remain.  These  concern  the  means 
whereby  we  secure  and  maintain  control  over  our  muscular 
movements  and  thus  become  able  at  will  to  give  expression 
to  our  thoughts,  our  wishes,  and  our  decisions.  There  are 
also  certain  large  general  aspects  of  volition  and  character 
which  merit  more  intimate  analysis  and  description  than 
they  have  hitherto  received. 

Stages  of  Motor  Control. — Psychology  is  under  no 
obligation  to  explain  the  existence  of  the  muscular  move- 
ments involved  in  voluntary  action.  From  the  beginning 

226 


ELEMENTS  OF  VOLUNTARY  ACTION  227 

of  a  baby's  life  these  movements  are  occurring  in  a  random, 
spontaneous  or  impulsive  way.  But  the  psychologist  may 
fairly  be  held  responsible  for  some  description  of  the 
manner  in  which  these  uncontrolled  movements  become 
organized,  as  ultimately  they  do,  into  effective  coordina- 
tions, like  writing  and  sewing.  In  Chapter  IV,  to  which 
the  reader  may  well  refer,  we  sketched  the  main  outstand- 
ing features  of  this  process  of  acquiring  motor  control, 
and  that  account  we  need  not  repeat,  although  we  must 
enlarge  upon  certain  phases  of  it. 

An  observer  watching  the  progress  of  a  baby's  mastery 
of  his  muscles  (as  in  learning  to  grasp  an  object  which  he 
sees),  might  well  remark  the  following  stages: 

(1)  A  first  period  in  which  undirected  impulsive  move- 
ments of  all   the  muscles   occur  in  response  to  sensory 
stimuli,  some  of  these  being  outside  the  body,  some  pre- 
sumably inside.1 

(2)  An  intermediate  period  in  which  a  few  controlled 
movements  of  the  larger  muscles  slowly  emerge.    The  con- 
trol is  very  imperfect  and  many  useless  movements  are 
always  included. 

(3)  A  final  period  in  which  skill  in  making  the  essential 
movements  is  achieved  and  the  superfluous  movements  fall 
away. 

(4)  New  coordinations  may  be  taken  on  at  any  time,  so 
that  the  three  stages  inevitably  overlap,  but  any  given  act 


1  Some  of  the  early  movements  are  of  course  instinctive  and  rep- 
resent pre-formed  pathways  through  the  nervous  system  The 
movements  here  referred  to  are  mainly  of  the  non-instinctive  type. 
The  pathways  are»opened  up  by  the  pressure  of  the  stimuli  coming 
in  over  the  sense  organs  and  are  not,  like  the  reflex  paths,  fixed 
and  substantially  uniform 


228  AN  INTRODUCTION  TO  PSYCHOLOGY 

passes  through  substantially  these  phases  on  its  way  to 
complete  control. 

Mental  Factors  Involved  in  Gaining  Control. — Such 
an  account  as  this  evidently  omits  all  reference  to  the 
mental  processes  which  accompany  such  a  course  of  develop- 
ment. Unfortunately  psychologists  are  far  from  unani- 
mous as  to  the  exact  nature  of  these  psychic  events.  All 
are  agreed  that  consciousness  is  energetically  employed 
during  the  process  of  acquiring  control,  and  that  it  tends 
to  subside  and  busy  itself  elsewhere,  as  the  coordination  is 
gradually  mastered.  All  are  also  agreed  that  sensations 
and  ideas  are  employed  in  gaining  motor  skill,  but  the  ques- 
tion as  to  just  how  they  are  used  is  a  source  of  radical 
disagreement.  Under  these  circumstances  it  will  perhaps 
be  most  helpful  to  the  reader  if  we  sketch  briefly  one  widely 
held  view  and  indicate  as  we  proceed  some  of  the  objections 
to  it. 

Let  it  be  understood  at  the  outset  that  the  main  points 
we  have  to  deal  with  are  (1)  the  nature  of  the  mental  cue 
by  which  a  particular  movement  is  called  forth  when 
desired,  (2)  how  this  cue  originally  got  its  power  to  serve 
as  a  motor  control,  with  special  regard  to  any  differences 
which  characterize  (a)  the  period  when  a  new  movement  is 
being  learned  and  (b)  the  period  after  it  has  become  rea- 
sonably automatic,  and  (3)  what  forms  of  mental  control 
are  employed  to  supervise  series  of  movements  such,  for 
instance,  as  are  used  in  piano  playing. 

Let  it  also  be  understood  that  we  have  no  obligation  to 
explain  the  fact  that  sensory  and  ideational  states  in  gen- 
eral lead  regularly  to  motor  consequences.  This  follows 
from  the  nature  of  the  sensory-motor  circuit,  which  has 
been  constantly  emphasized.  What  we  do  have  to  explain 


ELEMENTS  OF  VOLUNTARY  ACTION  229 

is  the  fact  that  a  particular  sensation  or  idea  is  followed 
by  a  particular  movement,  rather  than  some  other.  It  may 
also  be  remarked  at  once  that  normally  the  only  reason 
any  sensation  or  idea  fails  to  elicit  a  movement  is  that 
there  exists  some  blockage  in  the  neurones  or  that  it  comes 
into  competition  with  some  stronger  idea  or  sensation  and 
is  overcome. 

Owing  to  the  impossibility  of  ascertaining  just  what  goes 
on  in  the  child's  mind  while  he  is  learning  to  use  his 
muscles,  we  are  obliged  to  fall  back  upon  a  study  of  the 
behavior  of  adults  when  acquiring  new  motor  coordinations. 
Obviously  the  two  conditions  present  many  important  dif- 
ferences, but  we  must  make  the  best  of  the  situation. 

Part  Played  by  Sensations  and  Ideas  of  Movement. — 
Every  movement  of  the  voluntary  muscles,  however  caused, 
produces  kinaesthetic  sensations  and  is  apt  to  produce  other 
sensations  too.  For  example,  if  the  arm  is  raised,  we  feel 
the  movement  and  are  likely  also  to  see  it.  Now  one  view 
about  the  origin  of  voluntary  action  maintains  that  we  are 
so  organized  that  by  calling  into  mind  the  images  of  the 
kinaesthetic  sensations  aroused  by  any  spontaneous  or 
impulsive  movement,  we  can  again  elicit  the  movement 
itself.  The  development  of  voluntary  control  waits,  then, 
upon  the  accidental  occurrence  of  movements  which  catch 
attention,  whereupon,  by  recalling  the  memory  of  the 
kinaesthetic  sensations  aroused,  the  movements  may  be 
repeated.  Movements  presumably  catch  attention  most 
easily  when  they  produce  changes  in  some  object  already 
being  attended  to.  A  child  looking  at  a  red  ball  is  fairly 
sure  to  notice  the  movement  by  which  his  hand  comes  in 
contact  with  it.  Thus  little  by  little  the  various  muscular 
coordinations  will  be  mastered. 


230     AN  INTRODUCTION  TO  PSYCHOLOGY 

This  view  maintains  further,  that  as  control  grows,  there 
is  a  speedy  displacement  of  kinaesthetic  images  and  sensa- 
tions (called  'resident'  by  James,  because  they  arise  in 
the  part  moved)  in  favor  of  images  and  sensations  (called 
'remote')  reporting  the  objective  results  of  the  act,  rather 
than  the  mere  fact  of  movement.  The  auditory  word 
images  of  a  verse  we  wish  to  write  may  thus  serve  as  the 
only  cue  to  guide  the  hand,  the  kinaesthetic  imagery  being 
entirely  absent. 

Whether  this  general  theory  squares  with  the  facts  the 
reader  must  try  to  determine  for  himself.1 

Criticism  has  been  principally  directed  at  two  points.  It 
is  said  (a)  that  as  every  kinaesthetic  sensation  is  caused 
by,  and  occurs  after,  a  muscular  movement,  it  is  irrational 
and  contrary  to  the  general  neural  principle  of  habit  to 
suppose  that  the  sensation,  or  its  image,  can  again  bring 
about  the  same  movement.  If  effective  at  all,  it  should  call 
out  some  succeeding  movement  and  not  that  which  origi- 
nally caused  its  appearance. 

It  is  further  asserted  (b)  that  kinaesthetic  elements,  if 
employed  at  all,  are  merely  supplementary  to  other  kinds 
of  sensations  and  ideas,  and  that  they  probably  enjoy  but 
rarely,  if  ever,  any  such  primacy  as  is  imputed  to  them 
by  the  theory  we  have  been  considering.  Any  mental  cue, 

1  Shut  the  eyes  and  write  the  word  '  echo '  backward.  Then  try 
a  long  word  like  '  incomprehensibility.'  See  what  sensory  and 
imaginal  material  you  use  to  initiate  and  control,  the  movements. 
Try  similarly  some  relatively  novel  movement,  something  you  have 
not  done  before.  Men  can  easily  experiment  on  knitting  or  crochet- 
ing, women  can  try  some  unfamiliar  musical  instrument.  If  pos- 
sible, detect  what  mental  cues  you  employ  to  accomplish  the  neces- 
sary movements.  Be  sure  to  make  some  experiments  with  the 
eyes  closed,  to  bring  out  the  importance  of  visual  control. 


ELEMENTS  OF  VOLUNTARY  ACTION  231 

it  is  alleged,  may  be  used  to  elicit  a  movement,  provided 
only  that  by  some  combination  of  circumstances  it  has 
become  associated  with  the  latter  as  its  antecedent.  It  is 
generally  added  by  defenders  of  this  view  that  'imageless 
thoughts'  often  serve  this  function. 

Tentative  Formulation  of  Principles  of  Muscular 
Control. — Without  being  dogmatic  we  may  formulate  our 
views  on  certain  general  aspects  of  the  subject  as  follows: 
To  will  an  act  is  to  foresee  it  and  actively  wish  its  occur- 
rence. To  foresee  a  movement  implies  having  some  repre- 
sentative of  it  in  the  mind.  We  cannot  in  any  literal  sense 
anticipate  a  muscular  movement,  or  have  any  precise  idea 
of  it,  until  we  know  what  it  feels  like,  and  this  we  cannot 
learn  until  it  has  occurred  in  some  accidental  way.  The 
original  spontaneous,  impulsive  movements  afford  just  this 
necessary  information,  and  the  memories  of  the  movements 
and  their  results  afford  the  indispensable  mental  represen- 
tatives wherewith  to  think  of  them  and  thus  initiate  the 
process  of  wishing  and  willing  their  recurrence. 

Where  interest  is  centered  in  the  muscular  movement  for 
its  own  sake,  as  in  some  gymnastic  feats,  we  probably  use 
kinaesthetic  sensations  and  ideas  as  the  chief  medium  of 
control.  On  the  other  hand  when  the  interest  is  in  the 
objective  result  of  the  act,  as  in  most  of  the  occupations 
of  daily  life,  we  doubtless  make  predominant  use  of  other 
more  indirect  forms  of  control.  Whether  children  always 
begin  their  processes  of  motor  learning  with  the  kinaes- 
thetie  control,  we  cannot  say.  It  can  hardly  fail  to  play  an 
important  part.  But  in  the  adult  there  are  abundant 
instances  where  it  apparently  figures  in  only  a  very  minor 
way.  Certainly  as  expertness  is  gained,  in  any  act,  the 
controls  become  more  and  more  remote.  Any  idea  may  lead 


232  AN  INTRODUCTION  TO  PSYCHOLOGY 

through  an  associative  nexus  to  a  given  movement.  One 
may  open  a  window  in  order  to  look  down  on  the  street, 
or  in  order  to  air  out  the  room.  Two  quite  different  ideas 
thus  lead  to  the  same  act.  Moreover,  one  and  the  same  idea 
may  obviously  lead  to  very  different  reactions  as  when, 
desiring  to  find  a  coin,  one  first  explores  a  pocket  and  then 
a  desk  drawer. 

The  author  thinks  the  evidence  quite  clear  that  in  some 
cases  the  kinaesthetic  image  of  a  movement  actually  serves 
to  reinstate  the  movement,1  and  this  may  be  the  original 
tendency  of  all  such  mental  factors.  On  the  other  hand  it 
is  equally  clear  that  in  coordinated  series  of  movements, 
like  skating,  the  kinaesthetic  sensations  serve  as  the  cues 
for  movements  quite  different  from  those  which  called  them 
forth.  Kinaesthetic  images  may  well  operate  at  times  in 
the  same  fashion.  But  other  forms  of  sensations  and  ideas 
are  just  as  potent  in  motor  control. 

Reverting  to  the  three  points  mentioned  at  the  beginning 
of  this  discussion,  we  may  summarize  our  position  as 
follows : 

(1)  Any  sensation  or  idea  which  has  become  associated 
with  a  movement  as  its  antecedent  may  serve  as  the  mental 
cue  for  its  production. 

(2)  The  cues  first  used  are  the  memories  of  the  acci- 
dental spontaneous  movements  and  their  results.    Probably 
kinaesthetic  cues  are  more  largely  employed  in  the  early 
stages  of  motor  learning,  other  forms  speedily  sharing  this 
duty  with  them  and  after  a  time  tending  wholly  to  displace 
them.    Ideas  originally  altogether  disconnected  with  move- 

1  For  an  interesting  hypothesis  to  explain  the  neural  basis  of 
this  fact,  see  James'  Principles  of  Psychology,  Vol.  II,  Chapter 
XXVI. 


ELEMENTS  OF  VOLUNTARY  ACTION  233 

ments  may  thus  come  ultimately  to  serve  as  cues  for  their 
production. 

(3)  A  series  of  movements  once  initiated  may  go  on  with 
relatively  little  supervision,  but  in  many  cases  there  must 
be  constant  sensory  direction,  or  the  activity  will  go  adrift. 
Writing  affords  an  excellent  illustration.  The  control  may 
be,  and  generally  is,  carried  on  in  the  margin  of  the  field 
of  attention,  only  now  and  then  becoming  focal,  when  some 
difficulty  arises  which  requires  new  adjustment — e.g.,  when 
the  pen  point  catches  and  makes  a  blot.  The  sight  of  the 
word  or  the  pen,  the  kinaesthetic  sensations  from  the  hand, 
or  the  sound  of  the  pen  on  the  paper,  may  any  or  all  serve 
as  the  controls. 

Objective  Studies  of  Motor  Learning. — As  a  result  of 
many  experimental  studies  of  the  process  of  habit  forma- 
tion in  adults,  an  interesting  group  of  facts  has  been 
brought  to  light. 

If  we  arrange  to  measure,  hour  by  hour  or  day  by  day, 
the  rate  of  progress  made  in  the  mastery  of  a  new  accom- 
plishment, we  find,  contrary  to  a  common  impression,  that 
even  when  our  effort  is  substantially  constant  and  when 
ostensibly  the  difficulty  of  the  task  is  also  approximately 
uniform,  we  do  not  progress  at  a  constant  rate.  Sometimes 
we  go  very  much  more  rapidly  than  at  others,  and  now  and 
then  there  occur  considerable  periods  during  which  we 
seem  either  to  make  no  advance  or  actually  to  go  backward. 
The  accompanying  figure  51  represents  in  graphic  forte 
the  progress  made  by  a  person  learning  to  send  and  receive 
telegraphic  messages.  Similar  curves  are  available  for 
many  other  types  of  accomplishment.  It  will  be  seen  at 
once  that  the  curve,  instead  of  representing  a  straight 
upward-pointing  line  making  an  angle  of  forty-five  degrees 


234 


AN  INTRODUCTION  TO  PSYCHOLOGY 


with  the  base  line,  is  extremely  irregular,  sometimes  shoot- 
ing up  rapidly,  then  falling  back  again,  and  at  two  or  three 
points  presenting  roughly  a  level  region.  Such  a  region  is 
spoken  of  as  a  plateau.  These  are  zones  during  which  no 
advance  was  being  made,  as  measured  by  objective  achieve- 
ment. The  learner  was  performing  no  more  rapidly  at 
the  end  of  the  period  than  at  the  beginning. 

It  would  be  a  great  mistake  to  suppose  that  no  growth 


FIG.  51. — The  lower  horizontal  line  represents  the  number  of  weeks 
during  whicb  training  was  in  progress.  The  vertical  line  the 
number  of  words  which  could  be  sent  and  received  per  unit  of 
time.  (Modified  from  Bryan  and  Barter.) 

in  skill  is  going  on  during  these  days.  Some  experimenters 
have,  to  be  sure,  called  in  question  the  necessity  for  such 
plateaus.  But  whether  or  not,  under  occasional  ideal  con- 
ditions they  may  be  minimized,  there  seems  to  be  no  rea- 
sonable question  that  they  reflect  a  genuine  part  of  all 
familiar  learning  processes,  especially  such  as  definitely 
involve  the  attainment  of  motor  dexterity.  Apparently 
there  comes  a  point  at  which  the  nervous  system  has 
assimilated  as  many  new  pathways  as  it  is  for  the  moment 
capable  of  receiving,  and  before  profitable  advance  can  be 
made  in  the  using  of  such  paths,  there  must  be  an  appre- 


ELEMENTS  OF  VOLUNTARY  ACTION  235 

ciable  time  for  the  sinking  in  and  crystallizing  of  the  new 
connections.  After  these  have  become  firmly  established, 
a  new  set  may  then  be  built  upon  these  foundations. 

Distribution  of  Effort  in  Learning. — An  interesting 
corollary  of  these  observations  has  to  do  with  the  distribu- 
tion of  effort  and  time  in  any  process  of  learning,  but 
particularly  in  such  as  we  are  here  considering,  in  which 
motor  coordinations  are  being  established.  Various  opinions 
have  been  entertained  regarding  such  matters  as  the  length 
and  frequency  of  practice  periods  most  desirable  for  per- 
sons learning  to  play  a  musical  instrument.  There  is  a 
deep-seated  prejudice  among  many  music  teachers  that  the 
only  limitation  to  the  advantageous  length  of  a  practice 
period  is  set  by  fatigue.  The  problem,  conceived  in  a  large 
way,  is  still  in  its  infancy,  but  evidence  is  rapidly  accumu- 
lating which  strongly  suggests  that  very  much  briefer 
periods  of  practice  than  have  been  customary  are  for  many 
purposes  advantageous.  At  the  present  moment  no  one 
really  knows  in  any  precise  manner  how  many  sets  of  tennis 
may  best  be  played  each  day  in  order  to  secure  a  maximal 
proficiency  most  quickly.  The  judgment  of  experts,  how- 
ever, is  rapidly  growing  in  a  direction  which  would  confirm 
much  recent  psychological  experimentation  to  the  effect 
that  a  dozen  men  blunder  by  practicing  too  long  and  too 
often  for  one  who  blunders  in  the  opposite  direction.  When 
it  comes  to  a  question  of  increasing  mere  muscular  power, 
a  different  course  may  be  wise,  as  will  be  indicated  in  a 
later  chapter. 

We  have  already  had  something  to  say  about  this  matter 
in  connection  with  memory.  In  general,  it  may  be  laid 
down  as  reasonably  certain  that  while  "line  upon  line  and 
precept  upon  precept"  is  morally  wholesome  doctrine,  it 


236  AN  INTRODUCTION  TO  PSYCHOLOGY 

must  not  be  understood  as  meaning  that  judged  by  objec- 
tive achievement  each  hour  of  effort  expended  will  show 
an  equal  amount  of  tangible  outcome.  There  are  sure  to 
be  flat  regions  in  the  learning  curve  under  almost  all 
familiar  conditions;  but  these  regions  are  themselves  the 
preconditions  of  subsequent  rapid  advance. 


CHAPTER  XV 
WILL,  INSTINCT,  AND  CHARACTER 

Early  in  this  book  it  was  urged  that  we  find  acquired 
voluntary  acts  coming  in  to  help  out  the  short-comings  of 
our  hereditary  instinctive  equipment.  The  instinctive  acts 
appear  earlier  and  thus  seem  more  primitive,  and  the  volun- 
tary acts  are  apparently  built  upon  them.  There  is  another 
phase  of  the  relationship,  however,  which  deserves 
mention. 

Volition,  Attention,  and  Instinct. — Volition  in  its  de- 
veloped forms  involves  choice  among  possible  alternatives. 
These  choices  cannot  be  made  effective  until  we  have  control 
of  the  muscles,  but  the  necessity  for  making  them  would 
not  arise  were  there  not  competition  among  our  impulses 
and  instincts.  Attention  is  simultaneously  appealed  to  by 
two  or  more  stimuli,  by  two  or  more  instincts,  and  in  the 
nature  of  the  case  one  or  other  must  give  way,  unless  con- 
duct is  to  be  paralyzed.  Choice,  decision,  will,  in  the_ 
fullest  sense  of  the  word,  seems  to  arise  out  of  such  cir- 
cumstances, and  those  impulses  and  ideas  which  succeed  in 
gaining  our  persistent  attention  are  forthwith  translated 
into  action.  Willing  is  therefore  in  the  last  analysis  a  psy- 
chological process  of  attending.  When  only  one  competitor 
can  hold  attention  firmly,  choice  has  occurred  and  the  move- 
ments expressive  of  the  decision  will  take  place  at  the 
proper  moment,  in  accordance  with  the  procedure  sketched 
in  the  previous  chapter.  Volition  thus  establishes  organi- 

237 


238  AN  INTRODUCTION  TO  PSYCHOLOGY 

zation  among  instincts,  as  well  as  among  our  random  spon- 
taneous movements. 

If  volition  serves  to  organize  instinct,  instinct  no  less 
serves  to  furnish  the  most  imperious  motives  to  volition. 
Indeed,  it  is  not  too  much  to  say  that  all  the  great  per- 
sistent types  of  human  purpose  have  their  roots  in  instinct, 
and  that  the  evolution  of  character  in  man  is  essentially  a 
process  of  symmetrical  development  of  his  instinctive 
nature.  Where  some  one  instinct  or  group  of  instincts  suc- 
ceeds in  dominating  all  the  others,  the  result  is  a  one-sided, 
and  it  may  be  a  vicious,  character.  Or,  looking  at  the  situa- 
tion from  the  other  side,  the  absence  of  a  proper  develop- 
ment of  certain  instinctive  traits  may  produce  a  weak  and 
flabby  character.  At  all  events,  it  is  desirable  that  we 
should  consider  for  a  few  moments  certain  of  these  rela- 
tions of  instinct  to  volition. 

Persistent  Instinctive  Influences. — As  was  pointed  out 
in  Chapter  XIII,  one  of  the  earliest  of  these  instincts  to  find 
expression  is  undoubtedly  anger.  It  appears  on  the  slight- 
est provocation  whenever  appetites  or  desires  are  thwarted. 
Civilization  has  carried  on  a  long  and  relentless  struggle 
to  try  and  keep  the  expressions  of  it  within  reasonable 
bounds,  and  religion  and  ethics  alike  have  condemned  its 
manifestations  except  in  a  qualified  way  in  connection  with 
issues  involving  the  welfare  of  the  social  group.  Never- 
theless, there  are  probably  few  human  emotions,  few 
instincts  which  are  more  frequently  stimulated  and  which 
in  the  gross  play  a  larger  part  in  determining  human 
conduct.  Many  individuals  will  instantly  resent  the  impli- 
cation and  deny  the  truth  of  this  assertion.  But  if  one 
remembers  that  irritation,  exasperation,  annoyance  are  all 
names  for  rudimentary  forms  of  anger,  and  will  then  take 


WILL,  INSTINCT,  AND  CHARACTER  239 

the  trouble  to  trace  the  similar  rudiments  in  many  other 
emotions,  such  as  jealousy,  envy  and  moral  indignation, 
the  plausibility  of  the  assertion  will  be  recognized. 

Fear,  again,  is  one  of  the  earliest  and  most  persistent  of 
emotional  and  instinctive  motives.  Physical  fear  is,  thanks 
to  the  conditions  of  civilized  life,  a  far  less  frequent  expe- 
rience than  it  was  a  .few  centuries  ago.1  But  if  one  takes 
into  account  all  the  anxieties  that  connect  themselves  with 
ill-health,  with  precarious  social  and  economic  prospects, 
and  with  the  course  of  personal  affections,  to  mention  no 
other  phases  of  the  case,  it  will  at  once  be  seen  that  the 
shadow  of  fear  still  hovers  over  most  human  lives  in  a 
very  genuine  way. 

Turning  from  these  more  egotistical  instincts  to  those  of 
a  more  generous  and  socialized  type,  we  come  upon  the 
great  group  of  so-called  tender  feelings,  the  human  affec- 
tions, love  and  sympathy  and  pity,  each  of  which  plays  an 
important  part  in  every  normal  human  life,  and  in  some 
cases  an  altogether  predominant  part.  So  much  is  this 
the  case  that  in  certain  highly  organized  individuals  fear, 
at  least,  may  be  almost  wholly  abolished  except  in  that 
vicarious  form,  in  which  it  survives  as  anxiety  for  the 
welfare  of  others. 

These  considerations,  brief  as  they  are,  may  perhaps 
suffice  to  suggest  to  the  reader  the  essential  truth  of  the 
statement  that  instincts  play  a  dominant  part  in  determin- 
ing the  motives  of  voluntary  conduct,  and  in  keeping  alive 
the  vividness  of  interest  necessary  to  the  pursuit  of  a  dis- 
tant and  difficult  end.  One  other  aspect  of  the  case  ought, 
however,  to  be  brought  more  definitely  into  the  foreground. 

1  The  German  method  of  conducting  war  has  made  the  truth  of 
this  sentence  very  doubtful. 


240  AN  INTRODUCTION  TO  PSYCHOLOGY 

Transitory  Instincts. — The  instances  which  we  have 
chosen  as  illustrative  of  the  general  truth  under  discussion 
involve  emotions  which  characterize  somewhat  indifferently 
all  periods  of  life.  Certain  there  are  which  are  more  defi- 
nitely periodic  in  character,  belonging  to  particular  stages 
of  life  or  to  particular  forms  of  human  experience.  The 
adolescent  period  is  generally  characterized  by  a  much 
more  vivid  interest  of  the  sexes  in  one  another  than  is  met 
with  at  an  earlier  age,  and  of  a  character  in  some  par- 
ticulars quite  unique  as  compared  with  that  which  has  gone 
before.  This  type  of  interest,  once  developed,  may  extend 
indefinitely  throughout  later  life,  but  it  is  apt  to  be  most 
acute  in  its  earlier  stages  and  clearly  takes  its  rise  from 
the  radical  changes  in  the  bodily  organization  which  occur 
at  that  time.  As  compared  with  either  anger  or  fear,  this 
sex  instinct  is  evidently  more  definitely  limited  to  par- 
ticular periods  and  to  particular  situations  in  life. 

Of  a  similar  episodal  character  is  the  love  of  the  mother 
for  her  child,  an  instinct  which  obviously  can  have  no  full 
development  in  the  earlier  years  of  life  and  which  may  with 
childless  women  pass  largely  without  expression.  Despite 
the  somewhat  incidental  character  of  this  impulse,  there  is 
none  in  the  whole  range  of  the  human  instinctive  equip- 
ment capable  of  more  complete  domination  of  the  life  of 
the  possessor.  These  two  instances  may  serve  to  represent 
a  group  of  instincts  which  are  in  some  particulars  transi- 
tory, and,  as  compared  with  many  others,  of  a  distinctly 
more  periodic  character. 

Intellectual  and  Aesthetic  Impulses. — Although  un- 
doubtedly rarer  as  dominantly  controlling  influences  in 
life,  but  nevertheless  involving  a  genuine  instinctive  basis, 
should  be  mentioned  those  types  of  impulse  which  lead  to 


WILL,  INSTINCT,  AND  CHARACTER  241 

the  pursuit  of  definitely  intellectual  ends.  Thus  certain 
individuals  are  said  to  have  strong  scientific  interests, 
strong  scholarly  interests,  and  the  like.  These  spring 
undoubtedly  out  of  curiosity,  or  what  may  be  called  the 
hunting  instinct  in  its  intellectual  form,  the  play  instinct, 
and  the  instinct  of  construction.  Probably  no  great  scien- 
tist ever  lived  who  did  not  feel  an  overweening  inquisitive- 
ness  about  the  field  in  which  he  worked,  who  did  not  have 
something  of  the  thrill  of  the  hunter  elose  upon  his  quarry, 
who  did  not  find  the  pursuit  of  his  science  presenting  all 
the  thrill  and  cumulation  of  a  game,  with  something  of 
the  competitive  and  combative  instinct  called  out  by  the 
opposition  of  rival  scientists, — who  did  not,  in  other 
words,  carry  on  his  work,  however  purely  cold  and  intel- 
lectual it  appears  to  the  outsider,  with  much  of  the  fervor 
and  heat  of  the  primitive  animal  impulse. 

Similarly  the  artist  responds  in  his  professional  work  to 
a  group  of  motives  which  are  even  more  frankly  of  the 
instinctive  kind.  We  have  not  listed  in  the  catalogue  of 
instincts  any  reference  to  the  sense  of  beauty,  nor  would 
it  be  possible  to  include  in  any  single  term  all  that  is 
involved  in  the  constructive  artistic  impulse.  It  involves 
the  play  instinct,  it  often  involves  something  of  imitation, 
it  involves  strongly  the  tendency  to  self-expression,  it  has 
in  it  much  of  constructiveness,  and  it  is  saturated  with 
appreciation  of  beauty,  whether  of  nature,  of  one's  own 
artistic  production  or  of  that  of  others.  But  however  poor 
and  inadequate  our  terminology,  there  can  be  no  question 
that  with  many  individuals  the  impulse  for  artistic  con- 
struction predominates  over  most  other  motives,  and  that 
it  is  in  a  perfectly  real  sense  native.  No  doubt  all  of  us 
have  vestiges  of  these  more  intellectualistic  and  artistic 


242  AN  INTRODUCTION  TO  PSYCHOLOGY 

impulses,  but  viewing  mankind  in  the  large,  such  motives 
take  on  power  to  control  and  determine  the  careers  of  only 
a  few  individuals. 

Well  Developed  Character  Depends  on  Balance 
Among  Instincts. — What  we  had  in  mind  in  speaking  of 
the  development  of  volition  as  involving  organization  and 
balance  among  our  instinctive  propensities  will  perhaps 
now  be  more  obvious  than  before.  Certainly  on  the  nega- 
tive side  it  is  clear  that  a  life  dominated  by  impulses  of 
anger  or  of  fear  would  create  in  the  one  case  an  anti- 
social and  impossible  character,  and  in  the  other  a  morbid 
and  craven  individuality.  Over  against  such  one-sidedness 
may  be  set  the  extreme  sentimentalist  whose  entire  life  is 
a  mere  wallow  of  ill-directed  sympathy.  Such  persons  are 
the  curse  of  many  a  deserving  religious  or  ethical  institu- 
tion. Under  the  cloak  of  a  fine  and  pure  altruism  they 
represent  in  fact  a  spineless  and  flabby  tolerance  for  things 
and  persons  intrinsically  intolerable.  Not  unknown  is  the 
individual  so  inflated  with  vanity  and  self-esteem  as  to 
render  impossible  all  ordinary  social  relations.  But  little 
less  distressing  is  the  occasional  person  so  afflicted  with  self- 
abasement,  self-distrust,  and  timidity  as  again  to  render 
any  normal  participation  in  the  business  of  society  hope- 
lessly impossible.  Even  so  fine  an  instinct  as  that  of 
parental  pride  and  affection  may  be  exploited  to  a  point 
where  it  constitutes  a  neighborhood  nuisance  and  an  object 
of  ridicule  to  all  sane  folk. 

These  instances  will  surely  suffice  to  exhibit  that  which  is 
involved  in  a  reasonable  balance  of  our  instinctive  equip- 
ment. To  describe  with  precision  wherein  such  balance 
consists  would  no  doubt  be  difficult,  if  not  impossible.  But 
on  the  other  hand  there  is  no  particular  difficulty  in  dis- 


WILL,  INSTINCT,  AND  CHARACTER  243 

cerning  the  lack  of  balance  when  it  occurs  in  any  marked 
degree,  and  it  may  obviously  arise,  as  has  been  said,  either 
out  of  the  exaggeration  of  one  or  more  of  the  instinctive 
groups,  or  from  the  suppression,  partial  or  complete,  of 
others.  The  history  of  civilization  exhibits  the  process 
through  which,  little  by  little,  the  ordinary  individual  has 
come  to  develop  such  an  equilibrium  among  his  instincts 
as  will  permit  a  complex  organization  of  the  social  structure. 
A  moment's  reflection  will  serve  to  show  that  the  group  of 
instincts  most  essential  to  the  life  of  a  primitive  hunting 
people  will  differ  decidedly  from  the  group  of  those  re- 
quisite to  an  agricultural  form  of  life,  and  that  both  will 
make  quite  different  demands  upon  instinctive  traits  from 
those  needed  in  a  highly  organized  industrial  community. 
In  each  form  of  life  the  great  motive  powers  which  move 
the  individual  are  found  in  these  instinctive  springs,  but 
the  particular  balance  best  suited  to  one  economic  and 
cultural  stage  may  well  be  quite  different  from  that  essen- 
tial in  another. 

Volition  and  the  Sources  of  Our  Controlling  Interests. 
— The  view  has  been  presented  in  this  chapter  that  to  will 
is,  psychologically,  to  attend,  and  that  in  the  process  of 
attention  we  may  expect  to  find  the  crucial  features  of 
volition.  In  connection  with  this  doctrine  it  remains  to  add 
one  further  consideration,  to  wit,  that  the  direction  of 
attention  is  largely  determined  by  interest.  In  a  practical, 
common-sense  way  everyone  recognizes  that  the  mind  tends 
to  dwell  most  persistently  upon  topics  of  interest.  This 
fact,  when  translated  into  terms  of  conduct,  means  that 
we  tend  to  choose  those  lines  of  thought  and  action  most 
compatible  with  these  interests.  When  we  attempt  to 
catalog  and  classify  the  general  range  of  human  interests, 


244  AN  INTRODUCTION  TO  PSYCHOLOGY 

we  find  that  the  predominant  and  most  widely  distributed 
varieties  center  in  our  racial  instincts,  upon  which  we  have 
just  been  commenting.  Side  by  side  with  these  general 
types  which  we  share  with  all  our  fellows,  e.g.,  interest  in 
food,  in  warmth,  in  power,  and  in  social  prestige,  is  to  be 
placed  a  group  varying  from  individual  to  individual,  but 
derived  from  a  common  source,  i.e.,  such  tastes,  prejudices, 
and  talents  as  spring  from  our  personal  family  heritage  in 
contrast  with  our  human  racial  traits. 

In  every  community  there  are  certain  to  be  individuals 
enjoying  some  peculiar  capacity  which  by  common  repute 
has  come  down  by  inheritance  in  the  family  of  the  person 
concerned.  This  kind  of  thing  is  likely  to  escape  attention 
unless  the  talents  involved  are  of  a  somewhat  unusual 
order.  Nevertheless,  the  genuineness  of  the  facts  can 
hardly  be  called  in  question.  Here  is  a  child  early  mani- 
festing marked  interest  in  music  and  decided  ability  in  that 
direction.  Often  in  such  cases  it  will  be  found  that  one 
or  both  parents  enjoy  the  same  marked  characteristics,  and 
frequently  the  quality  can  be  traced  back  through  a  long 
ancestry.  Around  inherited  predispositions  of  this  kind  is 
likely  to  grow  up  a  set  of  interests  which  may  be  quite  as 
imperious  in  their  control  over  the  conduct  of  the  indi- 
vidual as  are  any  of  the  more  strictly  racial  tendencies. 
So  far  as  the  individual  himself  is  concerned,  interests  of 
this  character  are  quite  as  innate  as  any  of  the  more  purely 
instinctive  kind,  but  it  is  clear  that  they  represent  a  highly 
specialized  group  of  traits  which  for  some  unknown  reason 
have  developed  in  a  particular  stock  and  are  in  no  such 
degree  common  to  men  in  general. 

Even  more  striking  than  these  cases  of  inherited  family 
talent,  with  their  accompanying  intellectual  and  emotional 


WILL,  INSTINCT,  AND  CHARACTER  245 

interests,  are  the  rare  but  well  authenticated  instances  of 
the  occasional  outcropping  in  a  given  person  of  remarkable 
tastes  and  abilities  in  no  wise  to  be  discovered  in  any  of 
the  immediate  ancestors.  This  type  of  thing  represents  in 
an  extreme  form  what  is,  no  doubt,  in  lesser  degree  true  of 
all  men,  to  wit,  an  element  of  individual  variation,  carrying 
with  it  peculiar  abilities  and  interests  in  no  literal  sense  to 
be  found  in  any  other  individual.  The  genius  is  conspicu- 
ously of  this  type.  Perhaps  the  commonest  example  is  rep- 
resented by  the  appearance  of  marked  intellectual  interests 
and  unusual  intellectual  talent  in  the  child  of  wholly 
uneducated  and  commonplace  parents. 

It  appears,  then,  that  the  controlling  interests  of  any 
individual  may  derive  from  one  or  more  of  three  different 
sources:  (1)  racial  instincts,  (2)  family  traits,  and  (3) 
individual  variations,  representing  in  nervous  and  mental 
organization  what  the  botanists  and  zoologists  call  a  'sport,' 
that  is  to  say,  a  variation  which  cannot  at  present  be 
explained  in  any  ordinary  terms  of  inheritance.  As  the 
individual  grows  and  develops,  these  centers  of  interest  are 
necessarily  brought  into  relation  with  one  another,  and 
some  sort  of  organization  is  established.  Certain  interests, 
or  groups  of  interests,  gradually  tend  to  attain  mastery 
over  the  others.  It  must  not  be  supposed  that  this  state- 
ment implies  the  opposition  of  one  group  as  a  whole  to 
another  group.  The  controlling  system  may  have  in  it 
elements  from  all  three  sources,  and  it  is  often  extremely 
difficult  to  distinguish  influences  emanating  from  groups 
(2)  and  (3)  respectively,  Little  by  little,  however,  it 
comes  to  pass  that  there  is  established  a  certain  system 
under  which  our  daily  life  is  passed. 

Limitations  Upon  the  Response  to  Interests. — Nor  do 


246     AN  INTRODUCTION  TO  PSYCHOLOGY 

our  interests  merely  as  such  enjoy  a  free  fling  in  their  own 
cultivation.  The  rugged  and  obstinate  facts  of  the  phys- 
ical,, social,  and  financial  world  create  barriers  beyond 
which  we  cannot  pass,  and  within  which  we  are  obliged  as 
best  we  may  to  seek  fulfilment  for  our  desires  and  ambi- 
tions. The  direction,  however,  which  the  development  of 
our  conduct  and  character  takes  is  essentially  determined 
by  this  great  nucleus  of  interests.  Some  we  are  born  with, 
some,  in  a  sense,  we  seem  to  acquire.  But  whatever  the 
history  of  their  origin,  they  are  within  us  the  eternal  well- 
springs  of  our  energy  and  activity. 

An  interesting  instance  of  the  way  in  which  our  instinc- 
tive traits  are  molded  by  social  influences  is  exhibited  in 
the  facts  of  imitation.  Although  there  are  at  least  two, 
and  perhaps  more,  forms  of  imitation,  the  one  highly  nai've, 
essentially  reflex  and  characteristic  of  early  childhood,  the 
other  more  reflective  and  purposeful,  many  psychologists 
have  been  disposed  to  admit  the  essentially  instinctive  char- 
acter of  both.  Certain  it  is  that  our  mastery  of  most,  if 
not  all,  of  the  forms  of  social  intercourse  known  as  etiquette 
rests  upon  imitative  activities  in  which  the  individual  is 
obligated  by  social  pressure  to  follow  the  pattern  set  by 
usage.  The  occasional  social  anarchist  who  attempts  to 
flout  these  usages  speedily  finds  himself  an  outcast,  or 
established  in  the  unenviable  category  of  the  social  freak. 
From  earliest  childhood  on  we  are  subjected  to  the  inces- 
sant pressure  of  social  customs,  which  on  their  higher  levels 
appear  as  law,  or  as  moral  principles,  whose  rational  justi- 
fication is  sooner  or  later  urged  upon  us.  In  the  thousand 
and  one  eccentricities  of  local  or  national  usage  we  are 
thrown  back  for  our  acceptance  of  the  established  practices 
upon  a  purely  unrational  mandate  to  the  effect  that  "all 


WILL,  INSTINCT,  AND  CHARACTER  247 

well-bred  people  do  it."  To  defy  one  of  these  mandates  is 
to  exclude  one's  self  from  the  walks  of  polite  society. 
Why  should  one  lift  his  hat  to  a  gentleman  in  Germany, 
but  only  to  a  lady  in  America  ?  Why  should  one  entertain 
a  prejudice  against  the  use  of  a  steel  knife  for  the  purposes 
of  a  fork  in  polite  circles  in  the  United  States,  while  no 
such  prejudice  is  entertained  in  lower  circles  in  this 
country,  and  neither  in  high  nor  low  circles  in  certain  parts 
of  the  Continent?  Why  should  gentlemen  in  Europe  wear 
their  hair  short  and  in  Asia  long  ?  Why  should  ladies  wear 
skirts  in  Europe  and  trousers  in  Manchuria  ?  Why  should 
the  usage  be  exactly  reversed  for  men?  These  questions, 
have  no  rational  answers,  but  to  violate  the  dictates  of  the 
several  usages  involved  is  to  reap  a  form  of  social  whirl- 
wind which  few  persons  are  curious  or  courageous  enough 
to  experiment  with. 

Development  From  Muscular  to  Intellectual  and 
Moral  Control. — Looking  back  over  the  materials  of  the 
last  two  chapters,  it  will  be  seen  that  the  early  stages  of 
development  of  voluntary  control  are  necessarily  directed 
to  the  gaining  of  command  over  the  muscles ;  that  as  soon 
as  this  motor  control  is  established  we  proceed  forthwith  to 
make  our  muscles  the  tools  for  carrying  out  our  aims,  for 
securing  our  ends.  The  character  of  these  purposes  and 
aims  is  determined  in  the  first  instance  by  the  urgencies 
of  our  instincts  and  appetites.  In  the  early  stages  of  life, 
those  interests  which  are  most  immediately  related  to 
bodily  comfort  and  sustenance  are  in  the  foreground.  They 
never  wholly  lose  their  significance  for  us,  but  as  maturity 
is  gained  they  rapidly  lapse,  into  the  background,  giving 
way  to  other  forms  of  interests  connected  more  definitely 
with  our  social  and  moral  relations  and  with  the  growth 


248  AN  INTRODUCTION  TO  PSYCHOLOGY 

of  our  general  intellectual  life.  Not  the  least  important 
of  the  features  of  this  later  stage  of  our  development  is  our 
growing  control  over  the  process  of  thotight  itself.  The 
little  child  is  quite  incapable  of  sustained  reflection.  The 
disciplined  adult  is  able  to  give  himself  if  necessary  for 
hours  at  a  time  to  undiverted  thought  upon  his  own  future 
conduct.  This  gain  in  power  is  primarily  a  gain  in  ability 
to  hold  attention  to  a  process  of  thought.  When  a  decision 
is  reached,  the  line  of  conduct  selected  is  carried  out  by 
the  muscles  almost  automatically. 


SLEEP,  DREAMS,  HYPNOSIS,  AND  MULTIPLE 
PERSONALITY 

Over  against  our  waking  experiences,  with  which  our  dis- 
cussions have  hitherto  dealt,  are  properly  to  be  mentioned 
certain  facts  about  sleep  which  occupies  the  other  part  of 
our  lives  and  which  is  characterized  by  a  peculiar  form  of 
consciousness  of  its  own,  that  we  call  the  dream. 

Main  Facts  About  Sleep. — Despite  the  extended  and 
ingenious  experimental  investigations  of  sleep,  there  is  still 
among  physiologists  no  complete  agreement  as  to  its  causes. 
The  dogmatic  statements  which  are  often  made  about  it 
must,  therefore,  be  understood  as  expressing  the  opinion 
of  individuals  rather  than  the  final  verdict  of  science.  Cer- 
tain general  features  of  the  phenomenon  may  be  mentioned. 

Although  in  sleep  the  central  nervous  system  is  clearly 
less  excitable  than  during  waking  periods,  it  would  be  a 
mistake  to  think  of  it  as  in  any  sense  completely  inactive. 
Sensory  stimulations  which  in  waking  conditions  would 
produce  sensations  may,  in  sleep,  be  quite  ineffective;  but 
the  presence  of  dreams  and  of  certain  of  the  reflexes,  to 
say  nothing  of  the  activities  of  the  autonomic  system, 
whereby  the  vegetative  processes  of  the  organism  are  main- 
tained, show  clearly  that  neural  excitation  of  some  kind  is 
in  progress.  During  sleep  the  blood  vessels  of  the  brain 
are  relaxed,  and  the  pressure  in  the  entire  body  is  lowered. 
A  common  view  is  that  sleep  is  to  be  regarded  as  an  instinc- 

249 


250  AN  INTRODUCTION  TO  PSYCHOLOGY 

tive  reaction,  which  is  favored  by  conditions  of  moderate 
fatigue,  of  quiet,  of  habit,  and  of  expectancy,  although  no 
one  of  these  alone  may  be  able  to  induce  it  in  a  given 
instance.  There  seems  to  be  no  doubt  that  during  sleep 
the  waste  of  tissues  which  goes  on  during  the  waking  period 
is  repaired,  and  there  is  good  evidence  that  the  cell  bodies 
of  the  neurones  restore  certain  of  their  substances  which 
are  broken  down  during  waking.  Experiments  have  made 
it  quite  certain,  too,  that  under  normal  conditions  the  depth 
of  sleep,  as  measured  by  the  power  of  an  auditory  stimulus 
to  awaken  the  sleeper,  increases  for  about  three-quarters  of 
an  hour  to  an  hour,  then  falls  very  rapidly  until  between 
the  third  and  fourth  hour,  after  which  an  extremely  slight 
sound  may  cause  awakening. 

Dreams. — The  diversity  of  opinion  regarding  the  imme- 
diate causes  of  sleep  is  reflected  in  a  similar  divergence  of 
opinion  regarding  the  continuous  presence  of  dreams  dur- 
ing sleep.  Undoubtedly  the  commoner  view  today  is  that 
absolutely  dreamless  sleep  probably  does  not  occur.  Our 
frequent  inability  to  recall  dreams  is  attributed  to  the 
rapidity  with  which  we  forget  them  upon  awakening. 

There  is  little  question  that  the  stimulus  to  the  beginning 
of  a  dream  is  often  a  sensory  excitation,  a  sound,  the 
pressure  of  the  bed  clothing,  the  chill  of  a  draught  of  air, 
or  the  like.  But  once  the  dream  is  started,  the  course  which 
it  takes  is  apparently  controlled  by  much  the  same  associa- 
tive principles  as  we  have  previously  described  in  connec- 
tion with  memory  and  imagination,  but  under  little  or  no 
control  from  any  definite  purpose  or  intention,  such  as 
commonly  presides  over  our  trains  of  waking  thought. 

Freud,  the  Austrian  psychologist,  has  recently  urged  that 
all  dreams  represent  the  expression  of  suppressed  wishes 


SLEEP,  DREAMS,  AND  HYPNOSIS  251 

which  one  dares  not  frankly  confront  during  waking 
moments.  He  also  believes  that  the  particular  ideas  and 
images  in  which  the  dream  is  embodied  are  symbolic  and 
often  represent  situations  quite  other  than  those  immedi- 
ately suggested  by  the  images  themselves.  Freud  believes 
that  in  this  way  many  desires  and  wishes  are  cherished 
and  given  realization  in  the  dream  imagination,  which 
could  otherwise  gain  no  hearing,  because  of  their  hostility 
to  the  ideals  and  prejudices  of  the  waking  mind.  Thus 
one's  moral  convictions  might  altogether  prevent  the 
indulgence  overtly  in  acts  which  in  this  more  or  less  sym- 
bolic dream  form  are  freely  cultivated.  The  dream  thus 
offers  a  field  for  the  fruition  of  a  great  group  of  impulses 
and  desires  which  the  inhibitions  of  society  and  of  moral 
training  exclude  from  waking  experience. 

Fatigue. — Whatever  the  explanations  of  sleep  and 
dreams,  there  can  be  no  question  that  sleep  is  essential  for 
the  repair  of  the  physical  and  mental  exhaustion  coming 
from  work.  Fatigue  is  a  perfectly  normal  phenomenon, 
and  may,  indeed,  be  thought  of  as  essential  to  many  forms 
of  growth.  Certainly  no  one  can  secure  hard  and  well 
disciplined  muscles  who  does  not  use  them  to  the  point  of 
fatigue.  On  the  other  hand,  over-fatigue  may  be  a  very 
serious  matter,  and  any  type  of  experience  which  robs  us 
of  sleep  for  any  considerable  period  of  time  is  likely  to  be 
extremely  disastrous.  Experiments  have  made  it  fairly 
clear,  as  mentioned  above,  that  the  nerve  cells  undergo 
definite  physical  changes  under  excessive  use,  in  which  cer- 
tain of  the  tissues  contained  within  them  are  used  up. 
Similarly  it  has  been  shown  that  the  muscles  under  fatigue 
become  clogged  with  waste  material,  and  the  blood  is 
invaded  by  poisonous  elements  thrown  into  it  by  the 


252  AN  INTRODUCTION  TO  PSYCHOLOGY 

of  the  body  tissues.  Under  normal  conditions  the  recupera- 
tion from  fatigue  is  prompt  and  complete. 

Conditions  of  Effective  Work. — Evidently  the  highest 
efficiency  implies  such  a  combination  of  periods  of  work 
with  periods  of  rest  as  shall  enable  the  maximum  accom- 
plishment compatible  with  the  maintenance  of  the  organism 
in  robust  condition.  One  can  'spurt'  for  a  considerable 
period  of  time  under  pressure,  but  such  spurts  are  in- 
evitably followed  by  disproportionately  long  periods  of 
rest,  if  one  is  to  regain  one's  original  freshness.  Most 
individuals  organize  their  daily  lives  in  too  haphazard  a 
manner  to  make  this  matter  of  work  and  rest  of  any  great 
consequence.  This  is  another  way  of  saying  that  they  waste 
a  very  large  part  of  their  time  and  energy.  It  is  quite 
possible  to  ascertain  with  approximate  correctness  the 
length  of  the  intervals  during  which  one  can  work  intently 
to  advantage,  and  also  the  length  of  the  interval  of  rest 
which  may  best  follow  upon  such  occupation. 

For  the  average  person  of  sedentary  life,  engaged  upon 
intellectual  tasks,  an  hour  or  two  of  really  concentrated 
labor  is  likely  to  be  as  much  as  can  be  profitably  indulged 
without  respite,  if  one  is  to  work  successfully  day  after 
day.  It  is  often  said  that  the  only  rest  which  is  then 
needed  is  a  change  to  some  other  form  of  work.  But  the 
best  experimental  evidence  does  not  confirm  this.  The 
resting  interval  should  be  occupied  in  a  way  to  furnish  a 
minimum  of  mental  exercise  and  this  of  a  diverting  and 
recreative  character.  Mild  physical  exercise  is  good,  but 
severe  physical  activity  is  itself  tiring,  producing  an 
unfavorable  effect  upon  any  immediately  succeeding  mental 
operation.  The  best  studies  of  fatigue  indicate  quite 
strongly  that  mental  and  physical  fatigue  are  in  the  last 


SLEEP,  DREAMS,  AND  HYPNOSIS  253 

analysis  one.  The  length  of  the  interval  of  rest  ought  not 
to  be  so  brief  as  to  leave  one  still  feeling  dull  and  tired, 
and  on  the  other  hand  it  ought  not  to  be  so  long  as  to 
oblige  us  to  start  at  the  beginning  in  'getting  up  steam,' 
for  it  is  a  common  observation  that  in  undertaking  any 
serious  task  there  is  a  period  of  'warming  up.'  It  is 
obviously  in  the  interest  of  efficiency  to  abbreviate  this 
period  as  much  as  possible. 

Pillsbury  and  other  investigators  have  shown  that  indi- 
viduals vary  considerably  as  regards  the  time  of  the  day 
when  they  work  to  best  advantage.  This  does  not  mean 
that  the  ordinary  individual  is  incapacitated  for  work 
altogether  at  any  particular  time.  It  does  mean,  however, 
that  some  persons  can  accomplish  their  best  work  in  the 
morning,  some  in  the  afternoon,  and  some  in  the  evening. 
It  goes  without  saying  that  these  peculiarities  are  to  some 
extent  subject  to  training,  and  that  what  appears  to  be 
a  preference  for  one  of  these  periods  may  in  point  of  fact 
be  only  a  result  of  a  habit,  which  can  by  the  expenditure 
of  effort  be  changed. 

The  subject  of  sleep  and  dreams  leads  naturally  to  a 
few  comments  upon  certain  other  variations  of  normal  con- 
sciousness which  are  of  interest. 

Production  of  Hypnosis. — Hypnosis,  which,  as  the 
word  suggests,  is  a  state  in  many  particulars  closely  re- 
sembling sleep,  has  attracted  wide  scientific  attention  in 
recent  years.  Skilful  operators  can  transfer  a  person  in 
normal  sleep  to  a  condition  of  hypnosis.  But  ordinarily 
the  hypnotic  condition  is  induced  by  special  processes 
which  result  in  throwing  the  waking  patient  into  a  condi- 
tion at  first  resembling  light  slumber. 

There  are  many  methods  for  producing  hypnosis.    Some 


254  AN  INTRODUCTION  TO  PSYCHOLOGY 

are  successful  with  given  individuals,  but  fail  with  others. 
Practically  all  normal  persons  who  desire  to  be  hypnotized 
can  by  one  method  or  another,  if  the  attempt  is  repeated 
often  enough,  be  at  least  slightly  affected,  and  a  very  con- 
siderable number  can  be  drawn  into  the  deeper  forms  of 
hypnosis.  Whatever  the  detail  of  the  procedure,  the 
methods  all  have  in  common  the  fixing  of  attention  upon 
some  monotonous,  and  if  possible,  soothing  stimulus.  A 
common  device  is  to  'talk  sleep'  while  stroking  gently  the 
brows  of  the  patient,  occasionally  making  gentle  passes  with 
the  hands  down  over  the  arms  and  trunk.  Many  of  the 
earlier  operators  were  wont  to  employ  fixation  of  the  eyes 
upon  some  bright  object  held  a  little  above  the  bridge  of  the 
nose,  so  that  to  look  at  it  would  involve  a  fairly  pronounced 
strain  of  the  eye  muscles.  Other  operators  have  at  times 
used  the  ticking  of  a  metronome,  or  the  flashing  of  light 
from  rotating  mirrors.  Others  have  pressed  on  the  palm 
of  the  hand.  Once  a  subject  has  become  accustomed  to 
following  the  directions  of  the  operator,  who  assures  him 
from  time  to  time  that  he  is  falling  asleep,  almost  any 
signal  will  serve  to  bring  on  the  hypnotic  condition. 

As  in  normal  sleep,  the  subject  may  simply  become 
slightly  drowsy  and  then  arouse  again,  or  he  may  sink  into 
a  deeper  sleep  lasting  for  an  indefinite  period.  From  this 
sleep  he  may  ordinarily  be  aroused  by  the  command  of  the 
operator,  or  if  left  alone,  he  will  generally  wake  up  after 
a  little  while  of  his  own  initiative. 

Suggestion  in  Hypnosis. — Perhaps  the  most  striking 
feature  of  the  hypnotic  condition  is  the  patient's  remark- 
able susceptibility  to  suggestions  given  by  the  operator.  In 
waking  life,  we  are  all  subject  in  a  certain  degree  to  the 
effects  of  suggestion.  If  we  are  told  that  a  speck  high  up 


SLEEP,  DREAMS,  AND  HYPNOSIS  255 

in  the  sky  is  an  aeroplane  and  that  by  looking  sharply  we 
can  detect  the  wings  of  the  machine,  we  are  very  likely  to 
see  what  we  are  told,  even  though  the  object  be  a  bird  and 
not  a  flying  machine.  In  our  discussion  of  sense  perception 
we  had  occasion  to  remark  that  the  larger  part  of  the  things 
which  we  see  and  hear  are  perceived  in  accordance  with  the 
suggestions  given  to  us  by  the  physical  objects,  rather  than 
in  any  literal  sense  as  they  really  are.  But  in  hypnosis  this 
normal  suggestibility  is  much  exaggerated,  and  is  ordi- 
narily confined  to  the  words  and  acts  of  the  operator. 
Indeed,  as  we  have  intimated,  the  sleep  is  brought  on  by  a 
process  which  is  essentially  one  of  suggestion. 

People  vary  very  much  in  the  extent  to  which  they  are 
affected  by  hypnotic  suggestion,  and  they  tend  also  to 
become  increasingly  susceptible  under  repeated  hypnotiz- 
ing. In  describing  the  more  conspicuous  phenomena,  it 
may  be  understood  then  that  we  are  describing  conditions 
which  would  not  necessarily  present  themselves  in  any  one 
individual  in  the  earlier  hypnotic  experiences. 

Symptoms  in  Hypnosis. — We  may  roughly  group  the 
characteristic  phenomena  under  the  following  headings: 
(1)  sensorial,  (a)  anaesthesia  and  analgesia;  (b)  hyper- 
aesthesia;  (c)  hallucination;  (2)  amnesia,  i.e.,  loss  of 
memory;  (3)  motor,  (a)  paralyses;  (b)  catalepsies;  (4) 
post-hypnotic  effects. 

(1)  (a)  It  is  ordinarily  easy  to  produce  by  suggestion 
insensitiveness  to  contact  with  the  skin,  even  though  the 
stimulation  be  painful.  The  back  of  the  hand  may  thus 
be  rendered  insensitive,  so  that  it  will  not  be  moved  even 
if  cut,  pricked,  or  burned.  (1)  (b)  Similarly  it  is  not  diffi- 
cult to  produce  hypersensitivity  of  sense  perception,  as 
may  be  illustrated  either  in  visual  or  cutaneous  stimulation. 


256  AN  INTRODUCTION  TO  PSYCHOLOGY 

If  a  coin  be  pressed  upon  the  skin  of  the  forehead,  the 
normal  individual  can  generally  perceive  the  object  as 
circular  in  shape,  but  this  is  usually  all.  The  hypnotized 
person  may  be  quite  able  to  give  an  approximately  correct 
report  of  the  design  on  the  coin.  Again,  if  a  pack  of  fifty 
plain  cards,  like  calling  cards,  be  shown  to  the  hypnotized 
individual,  and  he  be  asked  to  note  one  in  particular,  he 
can,  after  the  cards  are  shuffled,  pick  out  the  original  with 
a  precision  far  excelling  that  of  the  ordinary  individual. 
To  make  this  test  it  is  of  course  essential  to  have  the  critical 
card  marked  on  the  reverse  side  in  some  way  to  permit  the 
experimenter  to  identify  it. 

(l)(c)  The  evidence  about  the  production  of  hallucina- 
tions is  somewhat  ambiguous,  but  it  is  generally  accepted 
that  in  the  deeper  hypnoses  at  least  they  may  be  encoun- 
tered. If  the  subject  be  presented  with  a  blank  piece  of 
paper  upon  which  he  is  assured  there  appears  a  sketch  of 
a  tree,  he  may  agree,  upon  being  asked,  that  he  actually 
sees  the  tree;  and  if  a  pencil  be  put  in  his  hand,  he  will 
ordinarily  trace  the  outline  of  the  fictitious  suggested 
object.  Despite  a  good  many  forms  of  control,  it  is  difficult 
to  be  sure  whether  in  every  such  case  the  subject  really 
sees  what  he  alleges,  or  whether  he  simply  gives  verbal 
assent  to  the  suggestion  and  adjusts  his  conduct  to  fit  the 
circumstances  as  the  operator  describes  them. 

(2)  There  is  great  variation  regarding  the  degree  to 
which  upon  being  aroused  from  the  hypnotic  sleep  different 
subjects  recall  what  has  gone  on,  but  after  deep  hypnosis, 
there  is  usually  almost  complete  forgetfulness  of  what  has 
occurred.  The  memory  of  the  period  is,  however,  obviously 
preserved,  because  in  a  subsequent  hypnosis  every  detail  of 
the  experience  may  be  recalled.  Moreover,  if,  during  the 


SLEEP,  DREAMS,  AND  HYPNOSIS  257 

sleep,  it  be  suggested  that  the  subject  will  recall  a  par- 
ticular circumstance  upon  awakening,  it  is  practically 
certain  to  be  remembered. 

(3)  (a)  One  of  the  most  easily  produced  results  and  one 
which  is  often  used  as  a  definite  symptom  of  the  presence 
of  genuine  hypnosis  is  the  inability  to  move  the  voluntary 
muscles,  especially  those  of  the  eyelids.    At  a  certain  point 
in  the  oncoming  of  the  hypnotic  sleep  the  operator  says: 
"Now  you  cannot  open  your  eyes";  and  sure  enough, 
struggle  as  he  may,  the  patient  finds  that  he  cannot  lift  his 
lids.     (3)  (b)  In  the  same  fashion  the  muscles,  if  put  into 
a  given  position,  the  suggestion  being  added  that  they  can- 
not be  moved,  will  remain  for  an  astounding  length  of  time 
rigid  and  tense.    Under  these  conditions  they  will  sustain 
a  strain  quite  beyond  their  normal  capacity.     The  stock 
exhibition  of  this  phase  of  hypnotic  phenomena  consists  in 
stretching  the  patient  out  with  head  and  heels  resting  on 
two  chairs  and  the  rest  of  the  body  unsupported.     This 
achievement  is  quite  beyond  the  muscular  powers  of  most 
individuals,  but  under  hypnosis  considerable  weight  may 
be  added  to  the  subject's  own  body  without  destroying  the 
muscular  resistance. 

(4)  Amazing   as    are   many   of   these    peculiarities    of 
hypnosis,  the  ability  to  carry  over  the  effects  of  suggestion 
into  the  subsequent  waking  life  of  the  subject  is  even  more 
striking.    The  therapeutic  value  of  hypnotism  has  generally 
been  regarded  as  depending  largely  on  this  feature.     A 
person  suffering  from  morbid  dreads  or  anxieties,  when 
assured  in  hypnotic  sleep  that  on  awakening  these  mental 
disturbers  will  not  be  encountered,  is  often  freed  from  the 
distress  and  suffering  for  a  considerable  length  of  time. 
The  most  scientific  treatment  of  nervous  and  mental  trou- 


258     AN  INTRODUCTION  TO  PSYCHOLOGY 

bles,  however,  is  not  today  made  dependent  upon  this  type 
of  direct  suggestion.  We  cannot  enter  here  into  any 
detailed  explanation  of  the  reasons  for  this  change  of  pro- 
cedure. Suffice  it  to  say  that  more  lasting  results  are 
gotten  in  other  ways.  The  point  here  is  that  suggestions 
given  during  hypnosis  are  often  carried  out  after  awaken- 
ing in  the  most  remarkable  way,  and  often  without  any 
consciousness  on  the  part  of  the  patient  that  he  is  executing 
commands  which  have  been  previously  given  to  him. 

For  experimental  purposes  a  common  type  of  demonstra- 
tion would  be  illustrated  by  an  operator's  instructing  a 
patient  to  return  at  a  certain  hour  three  weeks  later,  bring- 
ing with  him  some  quite  improbable  object,  like  a  basket  of 
fish.  Odd  as  it  may  seem,  in  nine  cases  out  of  ten  the 
patient  and  the  fish  will  be  forthcoming  at  the  time  and 
place  set.  Not  only  so,  but  the  victim  of  the  experiment  is 
fairly  certain  to  turn  up  provided  with  an  ingenious 
account  of  why  he  has  come.  Moreover,  the  whole  per- 
formance may  be  carried  out  without  suspicion  on  the  part 
of  the  subject  that  he  is  serving  the  cause  of  an  experi- 
mental demonstration. 

The  psychological  explanation  of  these  post-hypnotic  sug- 
gestions is  not  at  all  clear,  although  in  many  cases  what 
seems  to  happen  is  that  the  suggested  idea  begins  to  grow 
and  develop  and  justify  itself  from  the  time  it  is  first 
implanted  until  it  comes  to  fruition.  In  general  the 
explanation  of  hypnotic  behavior  is  far  from  certain,  and 
all  that  can  be  said  briefly  is  perhaps  that  most,  if  not  all, 
of  the  phenomena  encountered  appear  to  hinge  upon  the 
severing  of  the  marginal  portions  of  consciousness  from  the 
focus,  and  this  focus  appears  to  be  determined  by  the 
operator.  The  practical  effect  of  the  situation  is  to 


SLEEP,  DREAMS,  AND  HYPNOSIS  259 

eliminate  the  ordinary  inhibitive  influences  of  opposing 
ideas,  which  under  normal  conditions  would  enter  to 
modify  and  control  the  subject's  behavior.  Such  restrain- 
ing ideas  being  absent,  the  subject  carries  out  by  his 
actions  the  thoughts  which  are  thus  left  in  possession  of  the 
field.1 

Trance  Mediumship. — This  condition  of  hypnosis  pre- 
sents many  similarities  to  the  so-called  trances  of  the  spir- 
itualistic mediums.  Although  it  seems  necessary  to  admit 
that  a  considerable  proportion  of  the  professional  mediums 
are  fakes  and  charlatans,  there  is  no  question  at  all  that 
certain  individuals,  perhaps  victims  of  hysteria,  pass  from 
time  to  time  into  a  condition  where  they  become  more  or 
less  oblivious  to  ordinary  sense  impressions  and  either 
verbally  or  by  writing  express  the  thoughts  and  sentiments 
of  some  'spirit  control.'  Under  these  conditions  they 
purport  to  convey  information  and  advice  regarding  mat- 
ters of  which  they  are  themselves  entirely  ignorant.  Many 
of  them  have  laid  claim  to  supernatural  physical  powers, 
such  as  the  ability  without  physical  contact  to  lift  a  table 
and  hold  it  suspended  in  the  air.  In  practically  every 
case  M'here  these  pretended  supernatural  capacities  have 
been  carefully  studied,  they  have  been  found  dependent 
upon  clever  tricks  of  one  kind  or  another,  which  have  been 
successfully  repeated  by  stage  jugglers  and  magicians  whe> 
lay  no  claim  to  anything  but  cleverness  and  prestidigita- 
tion. Meantime,  the  trance  condition  is  undoubtedly  real 
in  a  certain  number  of  these  cases ;  but  it  does  not  follow 
that  the  alleged  clairvoyant  and  telepathic  powers  which 
these  persons  often  claim  have  any  basis  in  fact.  It  is 

1  No  inexperienced  person  should  attempt  to  hypnotize.  Serious 
harm  may  be  done. 


260     AN  INTRODUCTION  TO  PSYCHOLOGY 

fair  to  say,  however,  that  not  a  few  men  of  high  scientific 
standing,  and  perhaps  foremost  among  them  the  late  Pro- 
fessor William  James,  have  been  quite  convinced  that  some 
of  the  knowledge  possessed  by  the  trance  mediums  cannot 
be  explained  on  the  basis  of  our  ordinary  methods  of  sense 
perception,  nor  by  the  communication  of  ideas  from  mind 
to  mind  through  language  or  other  physical  signs.  It  is 
equally  fair  to  say  that  the  great  mass  of  competent  scien- 
tific opinion  is  quite  of  another  kind,  that  it  refuses  to 
recognize  any  appreciable  body  of  well-established  evidence 
calling  for  belief  in  telepathic  or  spiritualistic  communi- 
cations, whether  as  between  living  people  or  between  the 
living  and  the  dead. 

Multiple  Personality. — Just  as  the  phenomena  of 
dreams,  which  are  perfectly  normal  experiences  of  every 
human  being,  lead  us  out  gradually  into  phenomena  of  an 
essentially  abnormal  kind,  so  certain  conflicts  within  our 
characters  suggest  in  a  very  rudimentary  way  the  begin- 
nings of  abnormal  divisions  of  personality.  Few  more 
interesting  phenomena  have  been  studied  in  modern  psy- 
chology than  the  so-called  'multiple  personalities.'  Al- 
though in  the  last  analysis  the  several  varieties  are  prob- 
ably all  reducible  to  a  common  type  and  are  all  symptoms 
of  hysteria,  the  division  suggested  by  Alfred  Binet  is 
convenient  for  the  few  comments  which  we  can  make  upon 
the  matter.  He  distinguishes  successive  and  simultaneous 
alterations  of  personality. 

In  the  successive  form,  the  patient  may  wake  up  some 
morning  to  find  that  he  has  entirely  forgotten  all  his 
previous  life,  his  name  along  with  the  rest.  Whereas 
before  he  may  have  been  a  somewhat  lethargic  person  of 
equable  temperament,  he  is  now  extremely  active  and  of 


SLEEP,  DREAMS,  AND  HYPNOSIS  261 

somewhat  irascible  bent.  He  starts  in  to  build  up  a  new 
life,  oftentimes  disappearing  entirely  from  his  old  haunts. 
His  memory  processes  go  back  only  to  the  beginning  of 
his  attack,  but  from  that  point  on  they  may  be  entirely 
accurate.  Suddenly,  some  weeks  or  months  later  on,  he 
reverts  to  his  original  character.  The  memories  of  the 
secondary  state  disappear  wholly  or  almost  wholly,  and 
often  he  succeeds  after  a  time  in  getting  back  to  his  old 
home.  This  type  of  alteration  may  occur  again  and  again 
throughout  a  long  lifetime,  and  it  may  be  complicated  by 
the  introduction  of  two  or  three  more  similar  personalities. 
In  each  state  he  may  find  himself  more  or  less  completely 
cut  off  from  memory  of  the  other  alternating  states. 

In  the  case  of  the  simultaneous  multiplication  of  per- 
sonalities, it  is  as  though  these  successive  states  were  in 
some  fashion  telescoped  upon  one  another,  so  that  in  a 
certain  sense  they  co-exist  side  by  side.  It  is  extremely 
difficult  to  frame  any  readily  understood  picture  of  how 
this  kind  of  thing  may  go  on,  but  the  reader  may  with 
great  delight  to  himself  follow  the  dramatic  history  of 
one  such  case  in  Dr.  Morton  Prince's  Dissociation  of  a 
Personality.  In  this  case  there  is  a  constant  struggle  of 
the  several  personalities,  whose  characters  differ  from  one 
another  in  the  most  radical  way,  to  secure  control  over  the 
speech  and  conduct  of  the  afflicted  person.  Sometimes  one 
comes  out  ahead,  and  sometimes  the  other.  The  memories 
of  one  are  quite  hidden  from  access  to  some,  at  least,  of 
the  others. 

Subconscious  Processes. — These  cases  of  multiple  per- 
sonality of  all  varieties  exhibit  in  the  most  striking  way 
the  extent  to  which  subconscious  processes  may  operate. 
They  all  tend  to  suggest  that  the  divisions  underlying  these 


262     AN  INTRODUCTION  TO  PSYCHOLOGY 

disturbances  are  connected  with,  the  distinction  between  the 
focus  and  the  margin  of  our  awareness.  If  concentration 
becomes  highly  intense,  there  may  be  a  severance  of  the 
central  from  the  peripheral  regions  of  our  consciousness, 
and  what  goes  on  in  the  margin  may  then  get  itself  split 
off  as  a  type  of  subconscious  activity.  Obviously  elements 
which  are  represented  in  the  margin  may  in  no  true  sense 
be  really  lost  to  the  organism  as  a  whole,  but  they  may  be 
quite  completely  excluded  from  access  by  the  focal  parts 
of  the  mind.  In  normal  conditions  this  type  of  thing  is 
represented  when  we  become  so  absorbed  in  what  we  are 
reading  that  we  do  not  notice  the  striking  of  the  clock; 
and  yet  five  or  ten  minutes  later  we  may  'come  to'  and 
feel  quite  sure  that  although  we  did  not  notice  it  at  the 
time,  the  bell  was  actually  heard.  In  the  same  way  if  our 
attention  is  keenly  preoccupied,  we  may  do  the  most 
absurd  things  under  the  guidance,  more  or  less  sub- 
conscious, of  our  habitual  activities.  The  stock  instance  of^ 
the  man  who  goes  upstairs  in  the  early  evening  to  put  on 
evening  dress  preparatory  to  an  invasion  of  society,  only 
to  find  himself  in  bed  as  the  result  of  carrying  out  the 
operations  necessarily  begun  in  the  changing  of  his  attire, 
is  a  perfectly  good  example  of  this  type  of  thing.  Wh6 
is  there  that  has  not  become  so  preoccupied  when  on  the 
way  home  that  he  has  gone  far  past  the  proper  turning 
point  and  been  obliged  to  retrace  his  steps.  These  instances 
one  and  all  tell  the  same  story  of  the  part  played  by  the 
marginal  elements  in  our  awareness,  which  ordinarily  pre- 
vent our  cutting  too  completely  adrift  from  our  actual 
surroundings. 


CHAPTER  XVII 
THE  SELF 

It  has  been  necessary  thus  far  to  deal  with  the  several 
elements  of  human  behavior  to  some  extent  independently 
of  one  another,  although  certain  of  their  interconnections 
have  been  pointed  out.  We  have  found  the  mind  to  be  an 
adjustive  activity  making  use  of  sensory  and  ideational 
materials  in  order  to  gain  control  over  its  environment. 
We  have  noted  the  part  played  by  instinct  and  feeling  and 
emotion  in  determining  its  fundamental  attitudes  toward 
this  environment,  and  we  have  observed  something  of  the 
way  in  which  motor  coordinations  are  built  up  out  of  the 
raw  material  of  uncontrolled  movements,  until  adequate 
habits  are  finally  established  fit  to  cope  with  the  exigencies 
of  life.  We  have  remarked  throughout  all  this  process  of 
growth,  as  one  of  its  great  practical  results,  the  develop- 
ment of  character,  with  its  rational  principles  of  conduct, 
its  cherished  ideals,  its  established  modes  of  social  behavior. 
Now  it  behooves  us  in  conclusion  to  dwell  for  a  little  upon 
the  personal  self,  whose  experiences  we  have  thus  analyzed. 

The  Identity  of  the  Self. — There  is  a  deep-seated  popu- 
lar conviction,  resting  perhaps  as  much  on  tradition  as  on 
any  intuitive  or  reasoned  certainty,  that  the  self  continues 
in  some  way  unchanged  from  moment  to  moment  and  from 
year  to  year.  In  any  event,  contributing  to  this  convic- 
tion of  the  persistence  of  an  identical  self  are  many  factors, 
and  ranking  high  among  them  in  importance  is  undoubt- 
edly the  fact  of  memory.  I  can  recall  today  and  again 

263 


264  AN  INTRODUCTION  TO  PSYCHOLOGY 

tomorrow  the  events  of  last  year,  and  the  memories  of 
them  may  appear  very  similar  on  both  occasions,  may 
elicit  the  same  feelings  and  the  same  motor  reactions,  so 
that  I  come  naturally  and  without  much  reflection  to  de- 
velop a  sense  of  sameness  in  myself.  My  anticipations  also 
play  a  part,  for  again  and  again  there  recur  the  same 
desires  for  the  same  ends  as  yet  unattained.  Another  fact 
which  doubtless  contributes  to  the  total  result  is  my  fairly 
constant,  though  dim  and  vague,  awareness  of  my  own 
organism.  The  importance  of  this  consideration  is  sug- 
gested by  the  fact  that  any  serious  disturbances  in  the 
organic  sensations,  which  report  to  us  the  bodily  condi- 
tions, occasion  great  uneasiness  and  distress,  and,  if  pro- 
found, may  form  the  basis  of  malign  mental  disease.  Not 
least  striking  among  the  more  immediate  forms  of  evidence 
is  the  fact  that  after  sleep  or  any  form  of  unconsciousness, 
the  mind  normally  resumes  its  hold  upon  the  interrupted 
stream  of  events,  claims  its  own  out  of  the  past  and  goes 
on  as  though  no  interruption  had  occurred.  More  subtle 
is  the  contention  that  the  very  notion  of  consciousness, 
like  the  derivation  of  the  word  (con-scious-ness — knowl- 
edge over  against  something),  involves  a  subject,  a  per- 
sonal agent,  a  knower,  presumably  the  same  from  instant 
to  instant,  who  knows  the  particular  idea  present  at  the 
moment,  feels  the  pleasure  or  pain  and  wills  the  action 
determined  upon.  What  we  have  been  describing  in  this 
book  is  on  this  showing  simply  the  content  of  the  mental 
states  of  such  a  knower.  Finally,  philosophical  and  re- 
ligious speculations  have  furnished  an  impressive  body  of 
doctrine  concerning  the  perdurable  character  of  the  soul, 
which  tends  distinctly  to  confirm  this  widespread  convic- 
tion of  a  persistent  identity  in  the  self. 


THE  SELF  265 

Objections  to  the  Common  Idea  of  Self  Identity. — 
There  are,  however,  certain  facts  which  cannot  be  easily 
reconciled  to  this  view.  While  it  is  true  that  we  remember 
much  of  our  former  experience,  it  is  also  true  that  we  for- 
get much.  If  we  are  going  to  rest  the  unchanging  identity 
of  the  self  on  its  retention  of  its  own  past  in  memory,  it 
must  be  frankly  admitted  that  the  identity  is  only  partial, 
for  many  portions  of  one's  experience  fade  out  and  cannot 
be  revived.  Desire  and  anticipation  similarly  change  and 
develop,  despite  the  existence  of  a  core  of  such  desires 
which  may  remain  fairly  constant.  Obviously  the  self  at 
forty  years  of  age  is  better  informed  than  the  self  of  four, 
or  even  than  that  of  fourteen.  It  has  very  different  memo- 
ries, different  tastes,  prejudices  and  abilities.  Character 
at  these  different  stages  is  apt  to  be  widely  different.  Ob- 
viously, too,  the  physical  body  changes  in  very  marked 
ways  as  the  years  go  by,  and  to  some  extent  the  organic 
sensations  by  which  it  reports  to  the  mind  are  likely  also 
to  change — slowly  to  be  sure,  but  none  the  less  certainly. 
Furthermore,  the  cases  of  dissociated  multiple  personality 
described  in  the  previous  chapter  serve  to  show  how  flexible 
and  plastic  the  self  may  be.  All  things  considered,  there- 
fore, we  must  recognize  that  such  identity  as  the  self  pos- 
sesses is  probably  not  altogether  of  the  type  assumed  by 
common-sense  and  popular  tradition.  Two  additional  cir- 
cumstances should,  however,  be  noted. 

Continuity  of  the  Self. — There  is  (1)  undoubtedly  a 
continuity  in  the  life  of  the  self  which  is  in  one  respect 
like  that  possessed  by  all  living  organisms.  The  oak  tree 
is  different  in  almost  every  particular  from  the  acorn  from 
which  it  grew,  and  yet  we  speak  of  it  unhesitatingly  as  the 
same  tree  year  after  year.  It  has  a  continuous  life  and 


266  AN  INTRODUCTION  TO  PSYCHOLOGY 

this  fact  we  recognize  in  our  manner  of  speech  about  it, 
however  widely  its  appearance  may  vary  from  season  to 
season  and  from  decade  to  decade.  This  same  continuity 
of  life  man  obviously  enjoys,  but  beyond  this  is  the  fact 
that  he  knows  and  feels  this  continuity  as  the  plants  and 
many  of  the  animals  presumably  do  not.  This  continuity 
of  experience  does  not  for  a  moment  preclude  growth  and 
change,  as  the  more  rigid  and  static  conceptions  of  personal 
identity  seem  to  do.  It  rather  renders  such  alterations 
intelligible,  as  stages  in  the  evolutionary  adjustment 
of  a  living  mind  to  the  shifting  winds  of  cir- 
cumstance. 

Unifying  Tendency  of  the  Self. — Again  there  is  (2)  a 
very  genuine  sense  in  which  the  self  may  be  considered  as 
an  organized  unity.  Despite  the  fact  that  many  of  our 
experiences  are  lost  from  the  mind  through  forgetfulness, 
despite  the  facts  of  dissociated  personality  and  despite 
lapses  in  moral  behavior,  one  of  the  great  outstanding 
characteristics  of  normal  mental  phenomena  is  that  they 
tend  to  cohere  into  connected  personal  groups  with  syste- 
matic principles  of  organization.  Intelligent  processes  of 
adjustment  would,  indeed,  be  impossible  were  this  not  the 
case.  While  never  at  any  one  time  then  a  completely  and 
perfectly  unified  affair,  the  self  possesses  intrinsically 
unifying  and  organizing  tendencies.  As  long  as  it  con- 
tinues to  grow,  it  is  always  expanding  its  boundaries  and 
organizing  more  thoroughly  its  possessions. 

Thus  far  we  have  dealt  only  with  certain  general  aspects 
of  the  problem  of  the  self  as  this  emerges  from  popular 
tradition.  We  must  now  inquire  more  precisely  what  is 
the  actual  content  of  the  individual's  idea  of  the  self 
both  in  his  own  person  and  in  others.  This  will  lead  us 


THE  SELF  267 

to  examine  briefly  the  conditions  under  which  the  con- 
sciousness of  self  develops. 

Social  Origin  of  the  Idea  of  Self. — It  may  be  alleged 
with  reasonable  confidence  that  the  consciousness  of  the 
self  does  not  appear  ready  made,  but  that  it  is  a  result  of 
a  slow  process  of  growth.  There  seem  to  be  fairly  good 
reasons  for  believing  that  one  of  the  early  distinctions 
remarked  by  the  child  is  that  between  persons  and  things. 
Things  are  relatively  stable  and  uniform  in  their  modes 
of  behavior.  They  are  unmoved  by  the  child's  desires,  by 
his  gestures  or  his  cries.  Persons  on  the  other  hand,  while 
in  some  ways  more  variable  and  unreliable,  are  vastly 
more  responsive  to  the  child's  appeals,  and  they  minister 
to  his  comfort  and  the  satisfaction  of  his  desires  in  a 
manner  wholly  unique.  Moreover,  as  soon  as  sufficient 
motor  control  is  obtained  to  permit  this  indulgence,  per- 
sons afford  much  the  best  and  most  interesting  patterns 
for  imitation.  Such  imitation  repeatedly  brings  agreeable 
and  exhilarating  results.  Perhaps  most  important  of  the 
contributions  made  by  persons  to  the  emergence  of  the 
idea  of  the  self  is  the  gift  of  intelligent  speech.  And  not 
least  significant  in  the  use  of  language  is  the  fact  that 
the  child  is  referred  to  by  a  name  and  no  other  person 
or  thing  shares  it.  It  is  his  by  exclusive  proprietorship. 
The  personal  pronoiins  are  also  taught  him  and  gradually 
he  begins  to  read  into  them  correct  and  adequate  meanings. 
On  every  side  he  is  thus  surrounded  by  influences  which 
tend  (1)  to  draw  his  attention  to  personality,  as  con- 
cretely embodied  in  other  human  beings,  and  which  (2) 
strongly  impel  him  to  think  and  speak  of  himself  as  a 
person.  There  can  accordingly  be  no  question  that  the 
definite  consciousness  of  self  appears  amid  social  relations 


268  AN  INTRODUCTION  TO  PSYCHOLOGY 

and  in  response  to  social  incentives.  It  is  from  the  first 
a  distinctly  social  phenomenon. 

Content  of  the  Idea  of  the  Self. — What  particular  con- 
tent is  at  this  point  employed  to  fill  out  the  idea  of  self 
it  seems  very  hazardous  to  allege.  Later  on  in  life  when 
introspective  evidence  is  more  available,  we  find  quite  a 
variety  of  factors  reported.  To  think  of  the  self  is  ap- 
parently for  some  persons  simply  to  get  a  visual  image 
of  the  face  or  figure  as  it  appears  in  the  mirror.  Again 
it  may  involve  the  awareness  of  the  organic  and  kinaes- 
thetic  sensations  which  indicate  bodily  attftude  and  con- 
dition. Not  infrequently  it  is  a  concept  built  upon  one's 
surmise  of  the  esteem  in  which  one  is  held  by  others.  In 
this  case  it  is  likely  to  be  closely  identified  with  descriptive 
verbal  ideas,  e.g.,  'good  fellow,'  'able  man,'  'cad,'  'fool,' 
accompanied  by  emotional  attitudes  of  depression  or  ela- 
tion as  the  case  may  be. 

It  may  occur  to  the  reader  that  there  are  many  con- 
ditions designated  in  terms  of  'self  experience  to  which 
these  descriptions  are  quite  inapplicable.  Self-conceit, 
self-confidence,  self-distrust,  self-sacrifice,  self-conscious- 
ness— these  and  many  others  will  suggest  themselves.  On 
these  instances  two  comments  are  to  be  made.  In  the  first 
place  several  of  the  terms  apply  ordinarily  to  general  at- 
tributes of  character,  rather  than  to  specific  mental  experi- 
ences. Such  are  self-confidence,  self-conceit,  self-sacrifice. 
In  the  second  place  so  far  as  one  actually  feels  self-con- 
fident, or  self-conscious,  one's  thoughts  are  not  necessarily 
directed  to  the  idea  of  the  self  at  all.  One  who  feels  self- 
confident  may  be  contemplating  an  act  to  be  performed 
and  his  self-confidence  may  consist  simply  in  the  absence 
of  anxiety  and  worry.  The  self-conscious  person  is  likely 


THE  SELF  269 

to  be  afflicted  with  an  inconveniently  vivid  awareness  of 
his  own  organic  discomfort,  his  trembling  knees,  blushing 
cheeks  and  awkward  gestures,  but  there  may  be  in  his 
thought  only  the  most  remote  reference  to  the  idea  of  the 
self. 

It  appears  therefore  that  whatever  may  prove  in  a  given 
individual  to  be  the  content  of  his  'self  experiences,  the 
mind  is  only  incidentally  and  occasionally  engaged  with 
the  idea  of  self  and  only  now  and  then  attentive  to  the 
'I'  complex  of  organic  or  other  sensations.  A  constant 
attention  to  this  complex  is  one  of  the  symptoms  of  a 
neurotic  and  morbid  temperament.  The  fact  that  one's 
thoughts  and  feelings  all  belong  to  the  continuous  and 
more  or  less  unified  experience  of  a  self,  must  accordingly 
not  be  confused  with  the  unacceptable  doctrine  that  one 
is  always  conscious  of  the  self  as  such. 

There  is  one'  differentiation  of  the  idea  of  the  self  which 
is  based  upon  actual  differences  in  behavior  to  which  refer- 
ence should  be  made.  In  the  complexities  of  civilized  life 
a  man  may  be  called  upon  to  build  up  rery  different  habits 
of  adjustment  to  different  surroundings,  and  so  it  may 
come  about  that  the  Deportment  of  the  man  as  observed  by 
outsiders  may  well  suggest  very  divergent  types  of  char- 
acter. The  manager  in  the  office  at  the  mill  may  be  gruff, 
abrupt,  severe,  even  harsh.  The  same  man  at  home  may 
be  considerate,  gentle  and  affectionate.  His  companions 
at  the  club  may  encounter  still  a  different  person  and 
these  variations  of  conduct  may  be  multiplied  quite  in- 
definitely. For  each  of  these  'selves'  the  man  himself 
is  likely  to  entertain  a  somewhat  distinct  'self  idea,  al- 
though the  chances  are  that  in  his  own  appreciation  the 
several  selves  differ  from  one  another  far  less  than  appears 


270  AN  INTRODUCTION  TO  PSYCHOLOGY 

to  his  intimate  acquaintances  to  be  the  case.  Self  ideas 
of  this  type  are  very  apt  to  be  colored  by  regard  for  one's 
possessions,  one's  social  position  and  attainments,  and  this 
is  perhaps  especially  true  of  the  estimates  one  forms  of 
the  selves  of  other  men. 

Moral  and  Religious  Influences  upon  the  Self. — Moral 
and  religious  ideas  exhibit  peculiarly  significant  relations 
to  the  self.  The  ideas  of  right  and  wrong  get  their 
specific  content  in  the  course  of  the  individual's  moral 
development  and  through  his  reactions  to  the  rewards  and 
punishments  meted  out  to  him  by  society.  In  morals  as  in 
law  the  individual  finds  himself  treated  as  a  responsible 
agent  and  here  again  therefore  his  personality,  his  self- 
hood, is  projected  into  the  foreground  of  his  reflective 
attention. 

Religious  experience  in  this  respect  goes  even  further 
than  the  usual  moral  experience  in  that  it  compels  the  in- 
dividual to  think  of  himself  as  in  relation  with  a  Supreme 
Being  whose  character  is  such  as  his  own  may  become  by 
penitence  and  struggle.  There  is,  in  other  words,  pecu- 
liarly compelling  emphasis  upon  the  idea  of  companionship 
with  a  perfect  self.  • 

Types  of  Personality. — "One  of  the  most  interesting 
tasks  which  the  psychology  of  the  future  will  have  to  face 
is  that  of  delineating  the  various  typical  forms  in  which 
personality  reveals  itself.  But  at  present  such  descrip- 
tions cannot  be  more  than  rude  impressions  of  individual 
observers.  In  history  and  literature  a  few  of  these  great 
types  have  been  recognized.  We  meet  here  the  mystics, 
the  poets  and  dreamers,  the  seers,  some  of  them  fiery,  im- 
pulsive personalities,  others  gentle  ascetic  souls,  but  all 
of  them,  with  a  gift  for  vision  as  against  the  prosaic 


THE  SELF  271 

processes  of  tedious  reasoning,  and  with  varying  powers 
of  adequate  expression  for  their  insight.  Then  there  are 
the  scientists  and  scholars  with  a  religious  conviction  of 
the  worth  of  plodding  care  and  the  paramount  value  of 
facts.  Sometimes  this  trait  is  married  to  fervor  and 
emotional  tension,  sometimes  it  is  embodied  in  cold  calcu- 
lating temperament.  Then  we  find  the  great  leaders  of 
men,  the  military  and  industrial  geniuses  who  compel  by 
sheer  force  of  personality,  by  aggressive  capacity  of  hand 
or  brain;  the  religious  leaders  who  succeed  in  awakening 
the  spiritual  devotion  and  confidence  of  men.  The  average 
man  no  doubt  has  in  him  something  of  the  various  elements 
represented  by  all  these  great  types,  but  they  exercise  a 
less  imperious  sway  over  him  and  are  conjoined  with 
capacities  too  weak  and  commonplace  to  stand  out  boldly 
from  the  mass  of  humanity." 

Meanwhile  we  are  only  just  learning  how  important  it 
is  for  the  ultimate  welfare  of  society  that  each  man  shall 
be  placed  where  his  qualities  fit  him  to  serve  best,  and  our 
psychologists  are  doing  more  than  their  share  in  the  per- 
fecting of  methods  for  determining  the  special  combination 
of  mental  abilities  possessed  by  each  individual.  When 
these  methods  are  thoroughly  assimilated  into  our  educa- 
tional procedure,  we  may  look  for  a  vastly  higher  order 
of  human  efficiency  and  we  may  hope  for  a  much  higher 
average  of  human  happiness  and  contentment.  It  is  par- 
ticularly important  that  society  be  in  a  position  to  iden- 
tify and  exploit  the  useful  individual  variations  which  are 
now  often  hopelessly  submerged  and  lost  in  the  rough-and- 
tumble  methods  by  which  men  get  located  in  special  jobs. 
Once  settled  down,  the  misfit  may  go  through  life,  a  nui- 
sance to  himself  and  a  dead  loss  to  society. 


272 

Summary. — The  reader  is  now  doubtless  prepared  to 
appreciate  from  how  many  different  points  of  view  the 
self  may  be  approached  and  how  numerous  are  the  prob- 
lems it  presents.  In  this  chapter  we  have  examined  a 
few  of  the  considerations  bearing  upon  the  ideas  of  per- 
sonality prevalent  among  occidental  peoples  and  we  have 
tried  to  outline  some  of  the  more  familiar  and  tangible 
of  the  elements  to  be  discerned  in  the  consciousness  of 
self.  The  whole  book,  however,  is  nothing  but  a  sketch 
of  the  means  and  methods  by  which  intelligence  organizes 
conduct  and  develops  character.  The  result  of  this  process 
taken  in  its  entirety  at  any  given  moment  is  the  real  living 
self,  which  the  reader  will  find  most  fruitful  for  both  his 
practical  and  his  theoretical  interests. 


BIBLIOGRAPHY 


GENERAL  PYSCHOLOGY 

The  list  contains  (a)  a  few  standard  treatises  marked  with  an 
asterisk  and  (b)  texts  selected  because  they  differ  from,  or  dis- 
tinctly supplement,  views  presented  in  this  book. 

J.  R.  Angell,  Chapters  from  Modern  Psychology. 
M.  W.  Calkins,  Introduction  to  Psychology. 
John  Dewey,  Psychology. 
Knight  Dunlap,  A  System  of  Psychology. 
William  James,  Principles  of  Psychology,  2  Vols.* 

Psychology,  Briefer  Course. 
C.  H.  Judd,  Psychology,  General  Introduction. 
G.  T.  Ladd,  Psychology,  Descriptive  and  Explanatory.* 
R.  M.  Ogden,  Introduction  to  General  Psychology. 
W.  B.  Pillsbury,  Fundamentals  of  Psychology.* 
Josiah  Royce,  Outlines  of  Psychology. 
G.  S.  Stout,  Manual  of  Psychology.* 
E.  L.  Thorndike,  Elements  of  Psychology. 
E.  B.  Titchener,  Textbook  of  Psychology.* 
R.  M.  Yerkes,  Introduction  to  Psychology. 
W.  Wundt,  Outlines  of  Psychology.      (Trans.) 

MANUALS  FOR  EXPERIMENTAL  EXERCISES 

Requiring   no   apparatus: 

C.  E.  Seashore,  Elementary  Experiments  in  Psychology. 
Requiring  chiefly  simple  apparatus  easily  obtained: 
J.  V.   Breitweiser,  Psychological  Experiments. 
H.  F.  Hollingsworth,  Outlines  for  Experimental  Psychology. 
C.  H.  Judd,  Laboratory  Manual  of  Psychology. 
H.  S.  Langfeld  and  F.  H.  Allport,  Elementary  Laboratory  Course 

in  Psychology.      (Requires  some  elaborate  apparatus.) 
E.  C.  Sanford,  A  Course  in  Experimental  Psychology.     (Requires 

elaborate  apparatus  for  a  few  experiments.) 
L.  Witmer,  Analytical  Psychology. 

Requiring  for  many  of  the  Experiments  more  elaborate  apparatus: 
E.  B.  Titchener,  Experimental  Psychology,  4  Vols.     Qualitative 
and  quantitative  problems  are  treated  in  different  volumes, 
two  being  for  use  by  students  and  two  for  teachers. 

273 


274  BIBLIOGRAPHY 


PHYSIOLOGICAL  PSYCHOLOGY  AND  NEUROLOGY 

H.  H.  Donaldson,   The  Growth  of  the  Brain. 

K.  Dunlap,  Outlines  of  Psychobiology. 

C.  J.  Herrick,  Introduction  to  Neurology. 

Ladd  and  Woodworth,  Physiological  Psychology. 

J.  Loeb,  Comparative  Physiology  of  the  Brain  and  Comparative 
Psychology. 

W.  McDougall,  Primer  of  Physiological  Psychology. 
Body  and  Mind. 

C.  S.  Sherrington,  Integrative  Action  of  the  Nervous  System. 

W.    Wundt,   Principles   of   Physiological   Psychology.      (Trans., 
only  one  volume  thus  far  published.) 

T.   Ziehen,    Introduction    to    the    Study    of   Physiological   Psy- 
chology  (Trans.) 


SOCIAL  PSYCHOLOGY 

J.  M.  Baldwin,  Mental  Development,  Social  and  Ethical  Inter- 
pretations. 

F.  Boas,  The  Mind  of  Primitive  Man. 
C.  H.  Cooley,  Human  Nature  and  the  Social  Order. 
W.  McDougall,  Introduction  to  Social  Psychology. 
E.  A.  Ross,  Social  Psychology. 
W.  I.  Thomas,  Source  Book  of  Social  Origins. 
W.  Wundt,  Elements  of  Folk  Psychology    (Trans.). 


PSYCHOLOGY  OF  RELIGIOUS  EXPERIENCE 

E.  S.  Ames,  Psychology  of  Religious  Experience. 

W.  James,  Varieties  of  Religious  Experience. 

I.  King,  Development  of  Religion. 

J.  H.  Leuba,  Psychological  Study  of  Religion. 

J.  B.  Pratt,  The  Psychology  of  Religious  Belief. 

E.  D.  Starbuck,  Psychology  of  Religion. 

G.  M.  Stratton,  The  Psychology  of  the  Religious  Life. 


EDUCATIONAL  PSYCHOLOGY 

J.  M.  Baldwin,  Mental  Development  in  the  Child  and  the  Race. 

S.  S.  Colvin,  The  Learning  Process. 

F.  N.  Freeman,  Psychology  of  the  Common  Branches. 

How  Children  Learn. 
K.  Gordon,  Educational  Psychology. 
S.  Hall,  Adolescence,  2  Vols. 
W.  James,  Talks  to  Teachers. 

C.  H.  Judd,  Psychology  of  the  High  School  Subjects. 
E.  A.  Kirkpatrick,  Fundamentals  of  Child  Study. 


BIBLIOGRAPHY  275 

E.  Meumann,  Psychology  of  Learning    (Trans.)- 

R.  Schulze,  Experimental  Psychology  and  Pedagogy  (Trans.). 

D.  Starch,  Experiments  in  Educational  Psychology. 

E.  L.  Thorndike,  Educational  Psychology,  3  Vols. 


ABNORMAL  PSYCHOLOGY 

HYPNOSIS  AND  PSYCHOTHERAPY: 

H.  Bernheim,  Suggestive  Therapeutics. 

A.   Forel,   Hypnotism  and  Psychotherapy. 

A.  Moll,  Hypnotism. 

H.  Miinsterberg,  Psychotherapy. 

Worcester,  McComb,  and  Coriat,  Religion  and  Medicine. 
SLEEP  AND  DREAMS: 

S.   Freud,  Interpretation  of  Dreams    (Trans.) 

M.  de  ManaceTne,  Sleep,  Its  Physiology,  Pathology,  Hygiene  and 

Psychology. 
MULTIPLE  PERSONALITY  AND  HYSTERIA: 

A.  Binet,  Alterations  of  Personality. 

P.  Janet,   The  Major  Symptoms  of  Hysteria. 

M.  Prince,  Dissociation  of  Personality. 

Sidis  and  Goodhart,  Multiple  Personality. 
THE  UNCONSCIOUS  AND  THE  SUBCONSCIOUS: 

J.  Jastrow,  The  Subconscious. 

M.  Prince,  The  Unconscious. 
MENTAL  DISORDERS: 

A.  I.  Brill,  Psychoanalysis. 

A.  R.  Diefendorf,  Clinical  Psychiatry. 

H.  H.  Goddard,  Feeblemindedness,  Its  Causes  and  Consequences. 
SPIRITISM,  TELEPATHY,  ETC.: 

W.  F.  Barrett,  Psychical  Research. 

J.  E.  Coover,  Experiments  in  Psychical  Research. 

T.  Flournoy,  Spiritism  and  Psychology. 

J.  Jastrow,  Fact  and  Fable  in  Psychology. 

A.  Tanner,  Studies  in  Spiritism. 


VOCATIONAL  PSYCHOLOGY,  APPLIED  PSYCHOLOGY,  AND 
MENTAL  TESTS 

H.  F.  Adams,  Advertising  and  Its  Mental  Laws. 

Binet    and    Simon,    Development    of    Intelligence    in    Children 

(Trans.). 

S.  I.  Franz,  Mental  Examination  Methods. 
H.  L.  Hollingsworth,  Vocational  Psychology. 
H.  D.  Kitson,  How  to  Use  the  Mind. 
H.  Miinsterberg,  Business   Psychology. 
Psychology  of  Crime. 

W.  D.  Scott,  Increasing  Human  Efficiency  in  Business. 
Psychology  of  Advertising. 


276  BIBLIOGRAPHY 

L.  M.  Terman,  The  Measurement  of  Intelligence. 

E.  L.  Thorndike,  Mental  and  Social  Measurements. 

G.  M.  Whipple,  Manual  of  Mental  and  Physical  Tests. 

Yerkes  and  Bridges,  Point  Scale  for  Measuring  Mental  Ability. 


COMPARATIVE  PSYCHOLOGY 

A.  Forel,  The  Senses  of  Insects. 
L.  T.  Hobhouse,  Mind  in  Evolution. 
S.  J.  Holmes,  Evolution  of  Animal  Intelligence. 
H.  S.  Jennings,  Behavior  of  the  Lower  Organisms. 
Lloyd  Morgan,  Comparative  Psychology. 
Instinct  and  Experience. 
E.  L.  Thorndike,  Animal  Intelligence. 
M.  F.  Washburn,  The  Animal  Mind. 

J.    B.    Watson,    Behavior,    An    Introduction    to    Comparative 
Psychology. 


HISTORY  OF  PSYCHOLOGY 

J.  M.  Baldwin,  History  of  Psychology,  2  Vols. 
B.  Rand,  The  Classical  Psychologists. 


SPECIAL   TOPICS   IN   GENERAL   PSYCHOLOGY 

ATTENTION  : 

W.  B.  Pillsbury,  Attention. 

E.  B.  Titchener,  Psychology  of  Feeling  and  Attention. 
SENSATION  : 

Ladd  and  Woodworth,  Physiological  Psychology. 

McKendrick  and  Snodgrass,  Physiology  of  the  Senses. 
PERCEPTION : 

Ladd  and  Woodworth,  Physiological  Psychology,  Chapters  4,  5,  6. 
MEMORY  : 

E.  Meumann,  Psychology  of  Learning. 
T.  Ribot,  Diseases  of  Memory. 

H.  J.  Watt,  Economy  and  Training  of  Memory. 
lAfAGERY: 

M.   R.   Fernald,  Diagnosis  of  Mental  Imagery.     Has   extended 
bibliography.     (Psychological  Review  Monographs,  No.  58.) 

F.  Galton,  Inquiries  into  Human  Faculty. 
REASONING: 

A.  Binet,  Psychology  of  Reasoning  (Trans.). 
J.  Dewey,  Hew  We  Think. 
I.  E.  Miller,  Psychology  of  Thinking. 
W.   B.  Pillsbury,  Psychology  of  Reasoning. 
E.    B.    Titchener,    Experimental    Psychology    of    the    Thought 
Processes. 


BIBLIOGRAPHY  277 

FEELING : 

H.  R.  Marshall,  Pain,  Pleasure  and  Esthetics. 

H.  T.  Moore,  Sense  of  Pain  and  Pleasure. 

H.  M.  Stanley,  Evolutionary  Psychology  of  Feeling. 

E.  B.  Titchener,  Psychology  of  Feeling  and  Attention. 


K.  Gordon,  Esthetics. 

E.  Puffer,  Psychology  of  Beauty. 
EMOTION  : 

W.  B.  Cannon,  HodUy  Changes  in  Pain,  Hunger,  Fear  and  Rage. 

C.  Darwin,  Expression  of  Emotions  in  Man  and  Animals. 

T.  Ribot,  The  Psychology  of  Emotion. 
INSTINCT : 

See   Comparative  Psychology. 
WILL: 

T.  Ribot,  Diseases  of  Will. 

M.  F.  Washburn,  Movement  and  Mental  Imagery. 


INDEX 


Abnormal  psychology,  7. 

Accommodation   of   lens,  80. 

Acquisitiveness,   218. 

Affection,  as  elementary  phase 
of  feeling,  195. 

After-images,  91. 

Alternating  personality,  260. 

Amoeba,  19. 

Analysis,  sensory  and  intellec- 
tual, 70tf. 

Anger,  203,  205. 

Aphasia,  36. 

Association,  simultaneous,  74 ; 
successive,  IGOff. 

Association  centers  in  cortex, 
35/. 

Attention,  Chapter  V. 

Auditory  center,  36. 

Autonomic  system,  46ff. 

Axis  cylinder,  22. 

Axone,  22. 

BALDWIN,  223,  274. 

Blind-spot,   81f. 

Brain,  structure  and  functions 
of  and  connection  with  con- 
sciousness, Chapter  III. 

Brightness   sensations,   87/f. 

BRYAN,  234. 

CALKINS,  273. 

Calmness,  as  affective  element, 
190. 

Cannon,  208,   277. 

Cerebellum,  34/. 

Cerebral  laws,   160/. 

Cerebrum,  35/f. 

Character,  Chapter  XV. 

Child  psychology,  7. 

Choice,  see  Volition. 

Cochlea,  figs.  31-35. 

Color  blindness,  normal  per- 
ipheral, 83;  abnormal,  92. 


Color,  complementaries,  con- 
trast and  mixtures,  89/.y 
theories  of,  92/f. 

Comparative  psychology,   8. 

Concept,  nature  and  function  of, 
178ff. 

Consciousness,  appearance  of, 
49]^.;  relation  of  to  the  nerv- 
ous system,  Chapter  III. 

Coordinations,  establishment  of 
control  over,  Chapters  IV  and 
XIV. 

Cortex,  cerebral,   39)7. 

Cutaneous  sensations,  see  Sen- 
sations. 

DARWIN,  210,   277. 

Deduction,    184. 

Dendrite,  fig.  4. 

DEWEY,  209,  277. 

Disagreeableness  as  affection, 
lOOjfiF. 

Discrimination,  as  analytic  at- 
tention, 70ff. 

Dissociation,  see  Discrimina- 
tion. 

Double  personality,  see  Alter- 
nating personality. 

Dreams,  250. 

Ear,  figs.  31-35. 

Ego,  see  Self. 

Emotion,  Chapter  XII;  bodily 
factors  in,  370/f. 

Eustachian  tube,  fig.  31. 

Excitement,  as  affective  ele- 
ment, 190. 

Experimental    psychology,    6. 

Feeling,  Chapter  XI. 
Fovea,  figs.  23,  25,  27. 
FRANKLIN,  92. 


279 


280 


INDEX 


FREUD,  250. 
Fusion,  72ff. 

Generalization   in    thought,    171, 


Genetic  psychology,  7. 
Genius,  and  association,  165/. 
GORDON,  277. 

Grey,  sensations  of,  see  Bright- 
ness. 

Habit,  Chapter  TV. 
Hallucinations,   118. 
HARTER,   234. 
Hearing,   sensations  of,  Q4ff. 
Hypnosis,  253ff. 

Ideas,    connection    with    images, 

156/;   and   concepts,    175)7- 
Identity,   personal,   263/f. 
Illusion,  118/. 
Images,    function    of,    152)7;    re- 

lation  to   idea,    156/;   to   voli- 

tion, 229)7. 

Imagination,  Chapter  IX. 
Imitation,  as   instinctive,  218. 
Impulse,  215)7. 
Induction,   183)7- 
Instinct,     Chapter     XIII;     rela- 

tion to  emotion,  204. 
Interests,  nature  of,  243)7- 
Introspection,  3ff. 

JAMES,     114,     120,     137,     204, 

205,  206,   218,   232,  273. 
Jealousy,    357. 
Judgment,  174. 

Kinaesthetic,  sensation,  HO/.; 
function  in  establishment  of 
motor  control,  229  ff. 

LANGE,  205/. 

Lapsed  intelligence,  theory  of, 
222. 

MARSHALL,    277. 

Meaning   and    imagery,    159;    in 

reasoning,    175//". 
Medulla    oblongata,    33. 
Memory,   Chapter   VIII. 


Mood,    212. 
Motor   aphasia,   36. 
Motor  control,  Chapter  IV. 
Multiple  personality,  260. 
Muscular    sensations,    see    Kin- 
aesthetic. 

Nerves,   structure  of,   2lff. 
Nervous    system,    central,    29  ff.; 

autonomic,    46)7- 
Neurone,  definition  of,  2lff. 

Object,  perception  of,  114)7- 
Organic     selection,     theory     of, 


Pain,    its    relation    to    affection, 

190. 

Perception,  Chapter  VII. 
Personal  identity,  see  Identity. 
Physiological    psychology,    8. 
PILLSBURY,   219,    253. 
Pleasure,    as    affective    element, 

190)7. 

Productive     imagination,     159/. 
Psychology,     definition     of,      1  ; 

methods  of,  3ff.;  fields  of,  7ff. 
Psychophysics,   8. 

Race  psychology,   7. 

Reasoning,  Chapter  X  ;  in  brutes, 

185)7. 
Reflex    action,    relation    to    in- 

stincts,  2l5ff. 

Relations,  in  reasoning,   179/f. 
Relaxation,      as     affective     ele- 

ment, 190. 

Reproductive    imagination,    158/. 
Retention   of   material   in   mem- 

ory, 138/. 
Retina,  80f/. 
RIBOT,  219,  277. 
Rhythm,  133)7. 
ROYCE,  191,  273. 

Self,  Chapter  XVII. 
Semicircular  canals,  99)7- 
Sensation,  Chapter  VI.;  and  per- 

ception,  114. 
Sensations,    of    sound,    94)7-;    of 


INDEX 


281 


sight,  77tf.;  of  smell,  104)7.; 
of  taste,  101/f.;  of  tempera- 
ture and  touch,  108/f.;  or- 
ganic, 112/.;  of  movement, 
"Of. 

Sentiment,  212. 

SHERRINGTON,  274. 

Similarity,  association  by,  \63ff.; 
in  reasoning,  179. 

Size,  apparent  of  objects,   125/f. 

Skin-senses,  see  Sensations. 

Social  psychology,  7. 

Space,  see  Perception. 

Span,  or  scope,  of  conscious- 
ness, 61  ff. 

SPENCER,  221. 

Spinal  cord,  28ff. 

Strain,  as  affective  element,  190. 

Subconscious,  processes,  178,  261. 


Sympathetic  system,  46/f. 
Synaesthesia,  167/. 

Taste,  sensations,  see  Sensations. 
Temperament,  212. 
Temperature,  see  Sensations. 
Thought,  see  Reasoning. 
Time,   perception   of,    130/. 
TITCHENER,   273,  277. 
Touch,  see  Sensations. 
Twilight  vision,  87. 

Vision,  see  Sensations. 
Volition,  Chapters  XIV,  XV. 

WATSON,   208,   219. 
Will,  see  Volition. 
WUNDT,     190,    194,    222,    273, 
274. 


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